unity popcornfx ue4 editor mesh unity3d script shape-sampler unreal attribute plugin rendering particle unreal-4 collision animation spawn import crash pk-unityplugin error bug position ribbon android meshsampling effects unreal-engine-4 baking events fbx hh-unityplugin ios curve rotation camera image spawner compile-error vr billboarding shader sampler velocity evolver axis fx time sampler-shape distortion audiospectrum projection physics material audio api issues event attributes particles build spatial-layers projector unreal-collision dll animtrack blueprint ui lighting attractor preferences bake console builder delay flux scale scaling parent-field shape atlas id texture billboard model backdrop folder trail runtime popcorn #dllnotfoundexception hud nintendo depth-of-field evolverspawner draw-order plexus - cull time-multiplier