This section will describe the most common issues and how to solve them

Skeletal mesh particles

Since v2.14, a new BAT workflow is available for mesh particles.

Unreal Engine’s .fbx file import pipeline differs from PopcornFX Editor’s, meaning skeletons will not be imported the same way. If you generated a BAT in PopcornFX Editor from a newly created animated mesh, there’s a good chance importing that effect will produce bugged animations.

A quick fix (until we adopt a better solution) is to import the animated .fbx file in UE: this should create new Skeletal mesh, Skeleton and Animation assets.

Once this is done, re-export the Skeletal Mesh and Animations individually into your source PopcornFX project from UE’s content browser.

Re-generating BATs in PopcornFX Editor and re-importing your effect & BATs in Unreal will fix the bugged animations.

Note: This issue is due to the way UE imports and optimizes skeletons imported from .fbx files while PopcornFX Editor does not, leading to different skeletons in PopcornFX Editor vs UE.

Mesh atlases

PopcornFX Editor imports sub meshes from .fbx files while Unreal Engine .fbx import pipeline will create sub meshes (sections) based on sub meshes sharing the same material.

If importing an effect in UE using the Mesh Atlas feature renders all meshes instead of individual meshes:

• Make sure that in the source mesh (.fbx file), sub meshes have a unique material associated
• Make sure that when you imported the effect (or mesh) in UE, “Combine meshes” was enabled