Implement layered animation system for players and NPCs

kit commented

2026-03-17 00:51:01 +00:00

Owner

Players and NPCs in Source engine use a layered animation system where multiple animation sequences are blended together to create semi-dynamic movement — e.g., a walk cycle on the base layer with an upper-body gesture on top.

What needs to happen

Server side

Stream the active animation layers per entity: sequence index, cycle (progress), weight, playback rate
Source engine supports up to ~15 animation layers per entity — we need at least the first few
Bone transforms may need to be sent for entities using complex rigs (ragdolls, procedural bones)

Client side

MDL sequence parser: read animation data from .mdl/.ani files (bone transforms per frame)
Skeleton evaluation: given a set of weighted layers, blend bone transforms
Skinned mesh rendering: apply bone transforms to vertices via bone weights (already in .vvd data)
Interpolate animation cycles between ticks for smooth playback

Animation blending

Base layer: movement sequences (idle, walk, run)
Overlay layers: gestures, aiming, reloading — blended on top with per-bone masks
Layer weights control blend amount (0 = base only, 1 = full overlay)

Relates to

#5 (asset rendering — covers the MDL parsing foundation)
#2 (interpolation — animation cycles need smooth interpolation too)

Players and NPCs in Source engine use a layered animation system where multiple animation sequences are blended together to create semi-dynamic movement — e.g., a walk cycle on the base layer with an upper-body gesture on top. ## What needs to happen ### Server side - Stream the active animation layers per entity: sequence index, cycle (progress), weight, playback rate - Source engine supports up to ~15 animation layers per entity — we need at least the first few - Bone transforms may need to be sent for entities using complex rigs (ragdolls, procedural bones) ### Client side - MDL sequence parser: read animation data from `.mdl`/`.ani` files (bone transforms per frame) - Skeleton evaluation: given a set of weighted layers, blend bone transforms - Skinned mesh rendering: apply bone transforms to vertices via bone weights (already in `.vvd` data) - Interpolate animation cycles between ticks for smooth playback ### Animation blending - Base layer: movement sequences (idle, walk, run) - Overlay layers: gestures, aiming, reloading — blended on top with per-bone masks - Layer weights control blend amount (0 = base only, 1 = full overlay) ## Relates to - #5 (asset rendering — covers the MDL parsing foundation) - #2 (interpolation — animation cycles need smooth interpolation too)

kit referenced this issue

2026-03-17 01:05:07 +00:00

Asset rendering: models, NPCs, players, weapons, ragdolls, animations, materials #5

kit commented

2026-03-17 01:05:11 +00:00

Author

Owner

Part of the broader asset rendering effort in #5.

Related: #16 (position/rotation offsets) — some entity offset issues may be caused by missing bone/attachment transforms that the animation system would provide. Once this is in place, re-check #16 to see if some cases resolve.

Part of the broader asset rendering effort in #5. Related: #16 (position/rotation offsets) — some entity offset issues may be caused by missing bone/attachment transforms that the animation system would provide. Once this is in place, re-check #16 to see if some cases resolve.

kit referenced this issue

2026-03-17 01:05:14 +00:00

Investigate entity position/rotation offsets #16

Rows
Columns

Implement layered animation system for players and NPCs #9

What needs to happen

Server side

Client side

Animation blending

Relates to