feat(skills): ship ue-design-skills bundle, licensing and delivery gate
Phase 0 of the handoff plan, as a marketplace rather than a flat skills/ directory. Content moved out of the LyraResearch archive and depersonalised: addresses stay in the archive, recipes ship. - plugins/ue-design-skills: 17 skills, 232 failure-mode entries, each with the six required fields; catalog.json as the harness-neutral source of truth and .claude-plugin/ as one adapter over it. - _gate: 16 rules, one poisoned fixture per rule, plus surface coverage so a declared file cannot silently miss the line rules. - ADR-0002 (harness-neutral bundle behind a marketplace) and ADR-0003 (split licensing: CC BY-ND 4.0 prose, Apache-2.0 code and metadata). - LICENSE files at both levels, CONTRIBUTING.md, docs/licensing-options.md as the material the licence decision grew from. Verified: gate.py 0 violations; test_gate.py 16/16 rules redden on their fixtures with a clean baseline and 2 root files reaching the line rules. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
@@ -0,0 +1,406 @@
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# Failure modes: cosmetics and teams
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Eleven ways an appearance system or a team system produces the wrong result
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without producing an error.
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The shared property differs slightly between the two halves, and both are worth
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stating.
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**Cosmetics fail by looking almost right.** A wrong mesh, a missing part or a
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duplicated accessory is a visual outcome, and every visual outcome is plausible
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to code. Nothing can assert that a character looks correct, so these defects are
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found by people, late, and reported as "the skin is broken".
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**Teams fail by permitting.** Every interesting team defect resolves to
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"indeterminate", and the branch that handles indeterminate almost always allows
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the action, because denying it would have blocked something during development.
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Recipes use `rg` from a project source root and were executed against the audited
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project while this file was written.
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---
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## Cosmetics
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### CT-01 - The isolation guarantee is one line, and it is narrower than it looks
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**Mechanism.** Cosmetic presentation is excluded from the dedicated server by a
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single net-mode check at the spawn site. That check is the entire reason cosmetic
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content cannot influence authoritative simulation.
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**Why it is silent.** It works. On a dedicated server no presentation actor
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exists, so none can collide, block a trace or tick. The guarantee holds exactly
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where it is claimed.
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**Why the obvious check misses it.** The guarantee is usually restated as
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"cosmetics cannot affect gameplay", which is a stronger claim than the code
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makes. On a listen server or in standalone the parts **do** exist on the
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authority, with whatever collision and components their class carries. Nothing in
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the type system prevents a part class from containing an ability system or
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enabled collision — the constraint is content discipline plus one `if`.
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**Symptom.** A cosmetic accessory that blocks a shot, or a part actor that ticks
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expensively, in exactly the configuration used for local playtesting — and never
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on the dedicated server where the "real" testing happens.
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**Detect.** Find the guard, confirm there is only one, and check what part
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classes are permitted to contain:
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```bash
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rg -n "NM_DedicatedServer|IsNetMode" --glob "*.cpp" <cosmetics-module>/
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rg -n "CollisionMode|SetActorEnableCollision" --glob "*.cpp" --glob "*.h" \
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<cosmetics-module>/
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```
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In the audited project the first command returns **exactly one line** for the
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whole module. That is elegant and it is also the entire safety boundary, which is
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worth knowing before relying on it.
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**Guardrail.** State the guarantee accurately: "not present on a dedicated
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server", not "cannot affect gameplay". Validate part classes at author time —
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reject any that contain an ability system component, replicated properties or
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enabled collision by default.
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---
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### CT-02 - Every change rebuilds the actor
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**Mechanism.** The replication callback for a changed entry destroys the spawned
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presentation and spawns a new one, because propagating a diff into a live actor
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is hard and rarely needed.
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**Why it is silent.** It is correct. The result after a change is exactly the
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result after an add, which is what the system promises. The cost is a rebuild,
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and a rebuild looks identical to a first build.
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**Why the obvious check misses it.** The implementation is deliberate and
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commented as such. Reviewing it shows a decision, not a defect. The consequence
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only appears at a usage frequency nobody has yet — a system that changes parts
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rarely and one that changes them per second are the same code.
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**Symptom.** A hitch on every cosmetic edit. Discovered when a feature starts
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mutating parts at runtime — a preview screen, a colour cycler, a progression
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system — long after the mechanism was reviewed.
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**Detect.** Read what the change callback does, and compare it with the add path:
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```bash
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rg -n -A12 "PostReplicatedChange" --glob "*.cpp" . | rg -i "destroy|spawn|update"
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```
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If change is implemented as destroy plus spawn, treat the mechanism as
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add/remove only and design callers accordingly.
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**Guardrail.** Document the cost where authors will see it. If frequent edits are
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planned, add a real update path for the fields that can change in place, and keep
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the rebuild for the ones that cannot.
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---
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### CT-03 - Rule order is priority, and nothing says so
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**Mechanism.** A selection set is an array of rules, each with a set of required
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tags, plus a default. The first rule whose tags are all present wins. Rules are
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not sorted by specificity.
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**Why it is silent.** Every possible input produces a result — either a rule or
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the default. There is no "no match" state to report, and the result is always a
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valid asset.
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**Why the obvious check misses it.** The array looks like a set, and sets have no
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order. A reviewer checking "are the rules correct?" checks each rule in
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isolation, where each is correct. The defect exists only in the relationship
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between a broad rule and a narrower one below it, which requires comparing every
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pair.
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**Symptom.** A character with a specific tag combination gets the generic mesh.
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Nobody notices for weeks, because it is the *right kind* of mesh.
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**Detect.** Find selection sets and check for shadowing — a rule whose tag set is
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a subset of an earlier rule's:
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```bash
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rg -n -B2 -A6 "SelectBest|RequiredTags" --glob "*.h" --glob "*.cpp" .
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```
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Then, for each set, verify the shadowing property in a test rather than by
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reading: for every pair of rules `i < j`, assert that rule `i`'s tags are not a
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subset of rule `j`'s.
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**Guardrail.** Write the ordering rule as a comment on the array and enforce the
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subset check in validation. A rule that can never win is a content bug the
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compiler cannot see.
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---
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### CT-04 - The realization path re-applies unconditionally
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**Mechanism.** Recomputing appearance sets the mesh on every change broadcast,
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relying on the setter to be cheap when the value has not changed — while passing
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a flag that forces a pose reinitialization.
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**Why it is silent.** The result is correct. The mesh is right, the pose is
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right, and the cost is invisible at the frequency the system is normally used.
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**Why the obvious check misses it.** The code carries a comment explaining that
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the setter is a no-op when the mesh is unchanged, which answers the question a
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reviewer would ask. The forced flag is a separate argument on the same call, and
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it is not what the comment is about.
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**Symptom.** A visible pose pop or an animation reset whenever anything about
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cosmetics changes, including changes that do not affect the mesh at all.
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**Detect.** Check the arguments of the re-application call, not just the call:
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```bash
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rg -n -B6 "SetSkeletalMesh\(" --glob "*.cpp" . | rg "bReinit|true|Broadcast"
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```
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A hardcoded reinitialization flag on a path that runs on every change is the
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finding.
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**Guardrail.** Compare before applying, and pass the reinitialization flag only
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when the mesh actually changed. Idempotent realization means "applying twice
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costs nothing", not merely "applying twice is correct".
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---
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### CT-05 - Everything is a hard reference
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**Mechanism.** Part classes and selection-set assets are hard references, so the
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entire cosmetic catalogue is loaded with whatever holds the rules.
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**Why it is silent.** Hard references always resolve. Nothing is ever missing,
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nothing ever fails to load, and every asset is available the moment it is needed.
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**Why the obvious check misses it.** Reference correctness is what reviews check,
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and hard references are maximally correct. The cost is memory residency, which
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belongs to a different discipline and a different person, and which does not
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appear in any test of the cosmetics system.
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**Symptom.** Memory proportional to the size of the cosmetic catalogue rather
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than to what is worn, discovered during a platform memory pass and attributed to
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content rather than to a reference-type decision.
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**Detect.** Count hard versus soft references in the cosmetic data types:
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```bash
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rg -n "TSubclassOf<|TObjectPtr<" --glob "*.h" <cosmetics-module>/ | wc -l
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rg -n "TSoftClassPtr<|TSoftObjectPtr<" --glob "*.h" <cosmetics-module>/ | wc -l
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```
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A large first number with a zero second is the finding. See
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`ue-asset-loading-and-memory` for what this costs and how to measure it.
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**Guardrail.** Cosmetic catalogues are the textbook case for soft references and
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bundles: large, optional, and mostly unworn. Decide per field and record the
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decision in metadata.
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---
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## Teams
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### CT-06 - The mirror setter that silently does nothing
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**Mechanism.** Team identity is authoritative on one object and mirrored on
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several others. The mirrors implement the interface's setter because they must,
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and the implementation does nothing.
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**Why it is silent.** Doing nothing is correct — the mirror is not the owner. The
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call succeeds, returns, and the value is unchanged.
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**Why the obvious check misses it.** The setter exists and is implemented. Any
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review asking "does this type support setting a team?" answers yes. The caller
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has no return value to check and no reason to suspect the write did not land.
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**Symptom.** Code that sets a team on a controller or a pawn and observes the old
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value. The investigation goes to replication, then to ordering, then eventually to
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the setter.
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**Detect.** Read the bodies of every team setter and classify them:
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```bash
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rg -n -A4 "::SetGenericTeamId|::SetTeamId" --glob "*.cpp" . \
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| rg -B1 "UE_LOG|ensure|^\s*\}"
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```
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The audited project does this **correctly** and is worth copying: the mirror
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setters log an error naming the real owner rather than returning quietly. That
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one line converts an invisible failure into a searchable one.
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**Guardrail.** A mirror's setter logs an error identifying the authoritative
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owner. Never implement a no-op setter to satisfy an interface.
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---
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### CT-07 - The header promises a policy the body does not implement
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**Mechanism.** The damage-permission function is documented as taking friendly
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fire settings into account. The body contains no settings and no lookup.
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**Why it is silent.** The behaviour is coherent — allies are always safe — and
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that is the right default for most modes. Nothing malfunctions.
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**Why the obvious check misses it.** The comment *is* the documentation. A team
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adopting the system reads the header, concludes friendly fire is supported, and
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plans a mode around it. Discovering otherwise requires reading a body that looks
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finished.
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**Symptom.** A mode that needs friendly fire is scoped as a configuration change
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and turns out to be a design change, in a function every damage path depends on.
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**Detect.** Compare the promise with the implementation:
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```bash
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rg -n -i "friendly fire" --glob "*.h" --glob "*.cpp" .
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rg -n -i "bFriendlyFire|bAllowFriendly|FriendlyFireSetting" --glob "*.h" --glob "*.cpp" .
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```
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In the audited project the first command finds the promise in a header comment
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and the second returns **zero results project-wide**. A promise with no
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implementing symbol is the finding, and this recipe generalises to any header
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comment describing configurability.
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**Guardrail.** Treat a comment describing behaviour as a claim requiring a
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symbol. If the setting does not exist, the comment describes a plan and must say
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so.
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---
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### CT-08 - Indeterminate resolves to permitted
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**Mechanism.** Team comparison correctly returns three states. The damage rule
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treats the indeterminate case as allowed when the target satisfies an unrelated
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condition — in the audited project, having an ability system component.
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**Why it is silent.** It exists to make something work: an unassigned training
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target must be damageable. It succeeds at that, and the permissive branch is
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never reached by any assigned actor during normal play.
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**Why the obvious check misses it.** The function has three branches and handles
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all three, so it passes any review asking whether the indeterminate case is
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handled. It *is* handled — permissively — and the marker in the code says
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"temporary".
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**Symptom.** Any actor with an ability system and no team assignment is damageable
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by anyone. Harmless while the only such actor is a target dummy; a rule violation
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the moment a neutral faction, a destructible objective or an NPC exists.
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**Detect.** Find every consumer of the relationship enum and read its
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indeterminate branch:
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```bash
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rg -n -B4 -A10 "InvalidArgument|Indeterminate|NoTeam" --glob "*.cpp" . \
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| rg "return true|= true|Allow"
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rg -n -i "//\s*@?TODO.*(temporary|until)" --glob "*.cpp" .
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```
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The second command is the high-yield one: a permissive branch that its own author
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marked temporary is the strongest possible confirmation that the finding is real
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and known.
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**Guardrail.** Failure to determine must deny. Give the target dummy a team
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instead of giving every unassigned actor an exemption — solve the specific
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problem in data, not the general rule in code.
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---
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### CT-09 - A colour conversion that drops alpha
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**Mechanism.** A four-channel colour is converted to a three-element vector to be
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passed as a material parameter. The fourth channel is discarded.
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**Why it is silent.** Three of four channels arrive correctly, so the colour is
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right. Alpha is frequently unused in team colours, making the loss invisible for
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as long as nobody encodes anything in it.
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**Why the obvious check misses it.** The conversion is one token inside an
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otherwise correct call. Both types are colours, both are correct, and the review
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question — "is the parameter set?" — is answered yes.
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**Symptom.** A team parameter that encodes opacity or a blend factor silently
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reads as its default. In the same file, the effects-system path preserves all four
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channels, so the same asset behaves differently in two places.
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**Detect.** Find lossy conversions at parameter-setting sites:
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```bash
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rg -n "SetVectorParameterValue\w*\(.*FVector\(" --glob "*.cpp" .
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rg -n "SetVariableLinearColor|SetVectorParameterValue" --glob "*.cpp" .
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```
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Two applicators for the same data with different channel counts is the finding.
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In the audited project the material paths convert and the effects path does not.
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**Guardrail.** Pass four channels where the API accepts them. If a conversion is
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unavoidable, assert or document that alpha is unused.
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---
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### CT-10 - An accepted parameter that is ignored
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**Mechanism.** The display-asset accessor takes a viewer identity so that
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presentation can be relative — "my team always looks blue". The implementation
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does not read it.
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**Why it is silent.** The function returns the correct absolute asset. Every
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caller gets a valid result, and the feature the parameter implies has simply
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never been exercised.
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**Why the obvious check misses it.** The signature and the header comment
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describe the feature completely. Confirming absence requires reading the body,
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where the parameter is unused — and an unused parameter produces no warning
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because it is part of a virtual-looking public API.
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**Symptom.** A team implementing viewer-relative colours writes correct calling
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code and observes absolute colours. The bug appears to be in their code.
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**Detect.** For any parameter that names a feature, check that the body reads it:
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```bash
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P='ViewerTeamId'
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rg -n "\b$P\b" --glob "*.h" --glob "*.cpp" .
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```
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Occurrences only in the declaration and the definition's signature — with none in
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the body — is the finding. In the audited project the body carries a comment
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stating the parameter is currently ignored, which is honest and still ships an
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API that cannot do what it claims.
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**Guardrail.** Do not accept a parameter you do not use. Remove it, or implement
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it, or make the function name state the limitation. This is the same defect class
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as an ordering field that never sorts — see `ue-ui-architecture`, UI-01.
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---
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### CT-11 - "Private" that is not filtered
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**Mechanism.** Team data is split into a public and a private actor to express a
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replication boundary. The private one has no filtering; it is an empty subclass
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with a note that privacy is not implemented.
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**Why it is silent.** Everything works. Both actors replicate, both carry their
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data, and the split is structurally correct — it is only the *filtering* that is
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absent.
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**Why the obvious check misses it.** The architecture is visible and right: two
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types, two names, a clear intent. Reading the class names answers the question.
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Confirming means noticing that the private subclass has no body.
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**Symptom.** Data placed in the private actor because it is private is replicated
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to every client. Nothing indicates this until someone inspects network traffic —
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||||
or until a competitor does.
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||||
**Detect.** Check that the privacy-named type actually filters:
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||||
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||||
```bash
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rg -n -A15 "class \w*PrivateInfo|class \w*Private\w*" --glob "*.h" .
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rg -n "IsNetRelevantFor|GetLifetimeReplicatedProps|COND_" --glob "*.cpp" . \
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| rg -i "private"
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```
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An empty subclass, or one with no relevancy or condition logic, is the finding.
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||||
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||||
**Guardrail.** A name is not a mechanism. Either implement the filtering — via
|
||||
relevancy, replication conditions or a replication graph — or rename the type to
|
||||
what it is. In the meantime, do not put anything in it that matters.
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||||
@@ -0,0 +1,288 @@
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# Patterns: cosmetics and teams in a measured reference product
|
||||
|
||||
A worked example of both halves of `SKILL.md` against one reference project read
|
||||
as source. The two systems are presented together because the audit found what
|
||||
the skill claims: they touch at exactly one point, and both are well built on
|
||||
either side of it.
|
||||
|
||||
This file is unusually positive. That is the finding, not a tone: the
|
||||
architecture here is the strongest in the audited project, and the defects are
|
||||
narrow and specific. Separating "this design is worth copying" from "this
|
||||
implementation is finished" is the entire job.
|
||||
|
||||
Markers: **[measured]** — read in source; **[derived]** — conclusion from
|
||||
measured facts; **[open]** — not answerable from source, because the call site is
|
||||
in a binary asset.
|
||||
|
||||
---
|
||||
|
||||
## 1. The two-level split, and what it buys
|
||||
|
||||
```text
|
||||
controller component owns the desired part list, survives respawn
|
||||
│ on possession change: remove from old, apply to new, keep handles
|
||||
▼
|
||||
pawn component replicated list, spawns presentation, computes tags
|
||||
```
|
||||
|
||||
The controller component subscribes to possession changes **only on the
|
||||
authority**, and if a pawn already exists at subscription time it invokes its own
|
||||
handler with a null previous pawn **[measured]**. That second detail is the
|
||||
pattern's whole robustness: the same code path handles "pawn already here" and
|
||||
"pawn arrives later", so ordering stops mattering.
|
||||
|
||||
Transfer removes by handle from the old pawn and re-applies to the new, guarding
|
||||
against double-add by checking whether the handle is already valid **[measured]**.
|
||||
|
||||
**[derived]** This generalises well beyond appearance. Any state that belongs to
|
||||
the *player* and is realized on the *body* — loadouts, perks, temporary buffs —
|
||||
has the same shape and the same failure mode if you skip it: the state dies with
|
||||
the pawn.
|
||||
|
||||
The link from controller to pawn is found dynamically each time, with no cache
|
||||
**[measured]**. If the pawn has no cosmetics component the lookup returns null and
|
||||
nothing happens, silently — a tolerance that is correct for optional cosmetics and
|
||||
would be wrong for anything required.
|
||||
|
||||
---
|
||||
|
||||
## 2. Replicating intent, with the split declared in the type
|
||||
|
||||
One structure carries both server-only and client-only fields, distinguished by
|
||||
annotation rather than by having two types **[measured]**:
|
||||
|
||||
| Field | Replicated | Lives on |
|
||||
|---|---|---|
|
||||
| the part itself: class plus socket | yes | server → clients |
|
||||
| the handle returned to the caller | **no** | server only |
|
||||
| the spawned presentation component | **no** | client only |
|
||||
|
||||
**[derived]** This is the cleanest available demonstration of "replicate intent,
|
||||
realize locally". The wire carries a class reference and a socket name; the
|
||||
receiving machine reconstructs the appearance. Late join is deterministic because
|
||||
the state is compact and complete.
|
||||
|
||||
Change handling is deliberately coarse: the change callback destroys and respawns
|
||||
rather than propagating a diff, and the authors say so in a comment
|
||||
**[measured]**. Recipe: CT-02.
|
||||
|
||||
Part identity is defined as the pair (class, socket) and deliberately **excludes**
|
||||
the collision mode from the comparison **[measured]** — so two requests differing
|
||||
only in collision are the same part. **[derived]** That is a real decision about
|
||||
what identity means, made once, in the comparison function where it belongs.
|
||||
|
||||
---
|
||||
|
||||
## 3. The isolation guarantee, stated precisely
|
||||
|
||||
One line excludes presentation from the dedicated server, and it is the only such
|
||||
line in the module **[measured]**.
|
||||
|
||||
**[derived]** The consequence is strong and worth stating exactly: on a dedicated
|
||||
server the cosmetic actors do not exist, so they cannot collide, block a trace,
|
||||
tick, or influence the authoritative simulation in any way. That is a real
|
||||
architectural guarantee obtained for one `if`.
|
||||
|
||||
It is also narrower than the sentence people repeat. On a listen server or in
|
||||
standalone the parts exist on the authority, with whatever their class contains,
|
||||
and nothing in the type system prevents a part class from carrying an ability
|
||||
system or enabled collision. The other protections — collision defaulting to off,
|
||||
authority-only mutators, no ability-system includes anywhere in the module
|
||||
**[measured]** — are conventions and content discipline. Recipe: CT-01.
|
||||
|
||||
**The honest form:** *not present on a dedicated server*, not *cannot affect
|
||||
gameplay*.
|
||||
|
||||
---
|
||||
|
||||
## 4. The ten-line pattern worth stealing
|
||||
|
||||
An array of rules, each an asset plus a set of required tags, plus a default.
|
||||
Gather tags, walk the rules in order, first rule whose tags are **all** present
|
||||
wins, otherwise the default **[measured]**.
|
||||
|
||||
It appears at least three times in the audited project — body mesh, forced
|
||||
physics asset, and weapon animation layer **[measured]** — and costs roughly ten
|
||||
lines each time.
|
||||
|
||||
**[derived]** Its sharp edge is that priority is array order, with no weights and
|
||||
no specificity ranking. A broad rule above a narrow one silently shadows it, and
|
||||
the failure produces a plausible wrong asset rather than an error. Recipe: CT-03.
|
||||
|
||||
The tag namespace is declared in config and is deliberately small — a body style
|
||||
and two animation styles **[measured]**. **[derived]** Small is the right size:
|
||||
every tag in this namespace multiplies the rule matrix that has to be reasoned
|
||||
about.
|
||||
|
||||
---
|
||||
|
||||
## 5. Where the two systems touch
|
||||
|
||||
Exactly one place, and the code says so. The cosmetics component broadcasts a
|
||||
change with a comment noting that observers may need to apply team colouring
|
||||
**[measured]**; the team display asset applies material parameters to an actor
|
||||
**and its child actors by default** **[measured]** — and cosmetic parts are child
|
||||
actors.
|
||||
|
||||
**[derived]** That default is what carries team colour onto modular parts. It is
|
||||
one boolean default, and it is the seam.
|
||||
|
||||
**[open]** The actual call is made from a Blueprint: the applying function has no
|
||||
C++ caller. Which leads to the most important methodological point in this file.
|
||||
|
||||
---
|
||||
|
||||
## 6. What could not be answered, and why that matters
|
||||
|
||||
Four things in this subsystem have **no C++ call site** **[measured]**:
|
||||
|
||||
- who applies team colours to an actor;
|
||||
- who selects the weapon animation layer from cosmetic tags;
|
||||
- where the cosmetics component is added to a pawn;
|
||||
- where the controller component is added to a controller.
|
||||
|
||||
All four are wired in Blueprint or data assets, which are binary and were not
|
||||
read.
|
||||
|
||||
**[derived]** The correct conclusion is *"the wiring is in a place this audit
|
||||
cannot see"*, and the incorrect one — available, tempting, and wrong — is *"this
|
||||
function is unused"*. Both components are marked as spawnable from Blueprint
|
||||
**[measured]**, which is positive evidence for the first reading.
|
||||
|
||||
This is the general rule from `ue-reference-project-adoption`, met in its natural
|
||||
habitat: **absence of a C++ caller is not absence of a caller.** Anyone deleting
|
||||
"dead" code in a project with a large Blueprint surface needs the editor's
|
||||
reference viewer, not a text search.
|
||||
|
||||
---
|
||||
|
||||
## 7. Teams: one source, mirrors that refuse loudly
|
||||
|
||||
Membership lives on the player state, replicated push-based, authority-only, with
|
||||
a non-authority write logged as an error **[measured]**.
|
||||
|
||||
Every mirror — controller, bot controller, local player, pawn — reads through to
|
||||
the source, and their setters **log an error naming the real owner** rather than
|
||||
silently doing nothing **[measured]**.
|
||||
|
||||
**[derived]** This is the single most copyable line in the team system. A silent
|
||||
no-op setter on a mirror is indistinguishable from a working one until something
|
||||
depends on it; an error line converts an invisible failure into a searchable one,
|
||||
at a cost of one statement. Recipe: CT-06.
|
||||
|
||||
The pawn mirror is more subtle and also correct: it accepts a direct write **only
|
||||
while unpossessed**, and refuses with an explanatory error once a controller owns
|
||||
it **[measured]**. On possession it takes the controller's value and subscribes to
|
||||
its change delegate; on unpossession it unsubscribes and calls an overridable hook
|
||||
whose default is "no team" **[measured]**.
|
||||
|
||||
**[derived]** That hook is an extension point placed exactly where a neutral
|
||||
faction would need it, which is the difference between a design and an
|
||||
implementation that happens to work.
|
||||
|
||||
---
|
||||
|
||||
## 8. Resolution, comparison, and the one permissive branch
|
||||
|
||||
Resolution is a four-step cascade — interface, instigator, team-info actor,
|
||||
associated player state **[measured]**. **[derived]** The instigator step is what
|
||||
lets projectiles and area effects carry the shooter's team without owning one; a
|
||||
design that omits it grows a team field on every projectile.
|
||||
|
||||
Comparison returns three states rather than a boolean **[measured]**, which is
|
||||
correct and is what makes the next finding visible at all.
|
||||
|
||||
The damage rule permits four ways **[measured]**, and the third is the finding:
|
||||
when the relationship is indeterminate, damage is allowed if the target has an
|
||||
ability system component — with an author's comment marking it temporary until a
|
||||
training dummy gets a team assignment.
|
||||
|
||||
**[derived]** It exists to make one specific actor damageable and it generalises
|
||||
to every unassigned actor with an ability system. Harmless while the only such
|
||||
actor is a dummy; a rule violation the moment a neutral faction or a destructible
|
||||
objective exists. **Solve it in data — give the dummy a team — rather than in the
|
||||
rule.** Recipe: CT-08.
|
||||
|
||||
Friendly fire is promised by a header comment and implemented nowhere: a
|
||||
project-wide search for any friendly-fire symbol returns **zero** **[measured]**.
|
||||
Allies are unconditionally safe. Recipe: CT-07.
|
||||
|
||||
---
|
||||
|
||||
## 9. One policy function, two consumers — the pattern to copy
|
||||
|
||||
The same permission function is called by the authoritative damage calculation
|
||||
and by the client-side decision to show a hit marker **[measured]**.
|
||||
|
||||
**[derived]** This removes an entire bug class by construction. "The client showed
|
||||
a hit and the server dealt no damage" requires two implementations of one rule to
|
||||
disagree, and here there is only one implementation. Any project with predicted
|
||||
feedback should copy this arrangement before copying anything else in the team
|
||||
system.
|
||||
|
||||
The damage calculation consumes the result as a **0-or-1 multiplier** in the
|
||||
formula rather than as an early return **[measured]**. **[derived]** The team rule
|
||||
becomes an ordinary participant in the arithmetic, alongside distance and surface
|
||||
attenuation, which keeps the execution pipeline uniform and makes the rule easy to
|
||||
soften later — a scalar between zero and one is already expressible.
|
||||
|
||||
---
|
||||
|
||||
## 10. Presentation as named parameters
|
||||
|
||||
The display asset is a bag of named material parameters — scalars, colours,
|
||||
textures, a short name — not a set of assets **[measured]**. Materials are
|
||||
authored to expect the names, so adding a team costs one asset rather than a
|
||||
duplicated material tree.
|
||||
|
||||
Two defects in the applying code, both narrow:
|
||||
|
||||
- **Alpha is dropped** by the material paths, which convert a four-channel colour
|
||||
to a three-element vector, while the effects path preserves all four
|
||||
**[measured]**. The same asset therefore behaves differently in two consumers.
|
||||
Recipe: CT-09.
|
||||
- **A viewer identity parameter is accepted and ignored**, with a comment saying
|
||||
so **[measured]**. The signature and header describe viewer-relative colouring;
|
||||
the implementation returns the absolute asset. Recipe: CT-10.
|
||||
|
||||
Reactive binding is done well: an observation action broadcasts **immediately on
|
||||
activation** so a late subscriber gets current state rather than waiting for the
|
||||
next change, and a second action re-subscribes correctly when the observed team
|
||||
changes **[measured]**. **[derived]** Both are small patterns that eliminate a
|
||||
race, and both are reusable anywhere state is observed through a key that can
|
||||
itself change.
|
||||
|
||||
---
|
||||
|
||||
## 11. What to copy, in order
|
||||
|
||||
1. **One policy function for authority and prediction** (§9). Highest value,
|
||||
lowest cost, removes a whole bug class.
|
||||
2. **Loud mirrors** (§7). One log line per setter.
|
||||
3. **Controller-owned intent, pawn-owned realization** (§1), including the
|
||||
already-possessed case.
|
||||
4. **Non-replicated fields inside a replicated entry** (§2) — one type instead of
|
||||
two.
|
||||
5. **Rules-plus-default selection** (§4), with a shadowing check added.
|
||||
6. **Immediate first broadcast on subscription** (§10).
|
||||
|
||||
What to fix while copying: the indeterminate branch (CT-08), the friendly-fire
|
||||
gap (CT-07), the alpha conversion (CT-09), the ignored viewer parameter (CT-10),
|
||||
and the privacy that is a name rather than a mechanism (CT-11).
|
||||
|
||||
---
|
||||
|
||||
## Provenance
|
||||
|
||||
Measured against Epic's Lyra Starter Game on Unreal Engine 5.6: roughly 1300
|
||||
lines of cosmetics across 11 files and 1800 lines of teams across 22, read as
|
||||
source in a single workspace. Source addresses stay in the research archive that
|
||||
produced this skill; each `CT-` identifier resolves back to the audited location
|
||||
there.
|
||||
|
||||
## Evidence boundary
|
||||
|
||||
Four wiring call sites are in Blueprint or data assets and were not read; they are
|
||||
marked open above and nothing here depends on them. Everything else describes one
|
||||
project on one engine version. Re-run the recipes against your own tree before
|
||||
trusting any specific claim.
|
||||
Reference in New Issue
Block a user