This section covers motion blur problems.
Problem: Insufficient temporal sampling of shading or textures.
See MB Texture Samples in Render > Editors > Render Stats.
If the texture looks grainy, increase MB Texture Samples (under Render Stats) for the object. This marginally increases rendering time.
See MB Shading Samples in Render > Editors > Render Stats.
If the specular looks noisy, increase MB Shading Samples (under Render Stats) for the object. This noticeably increases rendering time; increase MB Shading Samples only when absolutely necessary.
Large objects do not motion blur correctly
A large object that stretches way beyond the view is clipped by the renderer. This clipping is done properly when the object is not motion blurred, but may clip incorrectly when the object is motion blurred.
See Mesh Tolerance (cm) in Render > Globals.
There are two possible causes:
See Motion Blur in Windows > Editors > Cameras.
Problem: Rendering with motion blur produces grid-like artifacts, or Rendering with motion blur causes triangles to disappear.
Some large triangles may extend beyond the camera and near clipping planes. Objects may be too close together, causing interpenetrating problems for motion blur.
Decrease the Mesh Tolerance value (under Render Globals). Move surfaces that may be too close together further apart.
Problem: Spot light shadows and light projections do not motion blur.
For shadows, blur the shadow by decreasing the Resolution (under Shadow Casting parameters). For projector lights, apply a solid projection texture to the object rather than using the light projection.
Solid textures do not motion blur correctly
This is a known limitation. Surface textures motion blur correctly.
See Convert Solid Tex in Render > Multi-lister.
If the moving object is a patch, use Convert Solid Tex and apply the pix file as a File texture.
See Project to UV - Apply Mapping in Render > Multi-lister.
Using warped objects and motion blur
Problem: Warped objects do not motion blur when warp parameters are animated.
When a warp parameter is animated, the resulting changes in the shape of the warped object are not motion blurred. An object moving through a warp will be motion blurred correctly.
Problem: Chatter in motion blurred textures moving behind transparent surfaces.
Motion blurred textures moving behind transparent surfaces may show chatter in the texture.
See MB Shading Samples in Render > Editors > Render Stats.
Problem: Motion blurred textures may appear streaked or noisy for fast moving objects.
See MB Texture Samples in Render > Editors > Render Stats.
See MB Shading Samples in Render > Editors > Render Stats.