Troubleshooting¶
Most problems announce themselves — in the baker's Output logs, or as a material compile error that names the setting to change. Check both before anything else.
Turning on Generate debug report (.md) writes a report next to your assets describing exactly what was baked. It's the first thing to check when a bake looks wrong, and the first thing to attach to a support request.
The mesh doesn't move at all¶
"No motion was captured — every frame is identical to the rest pose." The source never animated over the frame range. For simulated types, confirm the actor actually moves when you press Simulate. For Soft Body (Anim Sequence), confirm the sequence isn't a single static pose.
The material compiles but nothing happens. Always Evaluate World Position Offset is probably off on the material. Without it, a primitive's own WPO setting or WPO Disable Distance can suppress the animation entirely.
Frame isn't connected, or is connected to a constant. Drive it with Time × FrameRate.
The mesh disappears, or loses its shadow, when it moves¶
Max World Position Offset Displacement is too low. The compile error states the value to use. Unreal culls using the mesh's bounds plus this allowance; if the allowance doesn't cover the animation's travel, the mesh vanishes while its vertices are still on screen.
If you're using the Soft Body Scale input above 1, raise this setting by the same factor.
Shading is banded or faceted¶
The Normal (and Tangent) output isn't going through a Vertex Interpolator. Add one between the decode node and the material pin. Wired directly, the lookup runs per-pixel and bands across every triangle.
Lighting looks wrong / normals are inverted¶
Check Tangent Space Normal on the material:
- Both Soft Body types — must be ON
- Rigid Body and Fluid — must be OFF
Getting this backwards is the most common cause of odd shading. The node's compile error tells you which one it wants.
All the instanced pieces are stacked on top of each other¶
The PieceIndex input isn't fed by a PerInstanceCustomData node (index 0). Unreal only uploads
per-instance data to the GPU when that node is present in the graph — reading it any other way means
the data never arrives and every instance reads piece 0.
The instanced bake produced a combined mesh instead¶
The bake logged a warning and fell back to Compound. It requires every source actor to share the same static mesh at the same scale, with at least two pieces. Geometry Collections can never be instanced — their pieces are all unique shapes.
The warning in the Output logs names which condition failed.
Particles are missing, or too few appear¶
User.ParticleCount doesn't match the asset's Unit Count. Open the data asset, read Unit Count, and set the parameter to that number.
Particle playback jitters or particles swap places¶
"Emitter lacks 'Requires Persistent IDs'." Enable it on the source emitter and re-bake. Without it, particle identity isn't stable between frames.
Particles vanish and never come back¶
The graph is killing dead slots instead of hiding them. A slot dead at frame 0 may be alive later,
and a killed particle never returns. Use the Alive output to drive sprite size to (0,0) instead.
The fluid surface has holes or cracks¶
Holes: Max World Position Offset Displacement must be exactly 0 for Fluid materials. Any non-zero value turns hidden triangles back into visible geometry.
Cracks: re-bake at 128-bit (RGBA32F). The bake warns about this when you choose 64-bit; it's more visible on actors scaled up.
The bake stopped partway¶
"Capture aborted: the play world ended before the capture finished." The play session was stopped mid-bake. Let it run to completion, or use the panel's Cancel button.
Playback is choppy¶
Raise Capture FPS, or lower Frame Step. For Fluid, playback snaps to whole frames by design — smooth motion requires a higher bake frame rate.
The bake won't start¶
- "Set an Asset Name before starting a capture."
- "Select source actors and click 'Use Selected' before starting a capture."
- "Pick both a Skeletal Mesh and an Anim Sequence before baking."
"Bake is too large for a single texture"¶
Reduce the frame range, raise Frame Step, or reduce the number of pieces/vertices/particles in the source.
Re-baking says the source can't be found¶
Re-baking from a data asset restores the original settings, but level actors are resolved by reference — if the level changed or the actors were renamed, re-select them. For Soft Body (Anim Sequence), re-pick the mesh and sequence.
After updating the plugin¶
If a release note says the format changed, re-bake your assets. Old bakes may not play back correctly against a newer decode node.