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Motion Blur
Krakatoa Motion Blur
Krakatoa provides a built-in method for motion blur, which computes the motion blur samples after shading and lighting have occurred. This method is very fast and should be the preferred mode in most cases.
Advantages
- Customizable shutter timing
- The effect is based on the current position and the current velocity vector of each particle, meaning that the particles have to be loaded and lit just once and each Motion Blur pass takes as long as the final pass (sorting and drawing particles into the frame buffer). In short, it is VERY fast and allows for high segment numbers with little time penalty.
- The shutter bias used for matte objects can be customized to match the shutter bias in the geometry rendering.
- Jittered Motion Blur results in a more randomized noise pattern.
Disadvantages
- When rendering particles, the shutter is always centered.
- Moving Matte Objects are supported at Position/Rotation/Scaling transformations level but Motion Blur does not account for geometry deformations yet. (If you are rendering quickly deforming meshes, you should use the 3ds Max Multipass Motion Blur effect instead which will recalculate the particles and geometry on each sample).
3ds Max Multi-Pass Motion Blur
The 3ds Max multi-pass motion blur method is supported for the few cases where the disadvantages of the built-in method are more significant than the advantages. This mode should be used when the particle system has really complex motion, or when the matte objects have fast vertex animation/deformations applied to them. Both the advantages and disadvantages of the 3ds Max method are caused by its modus operandi:
Advantages
- The 3ds Max Multi-Pass Motion Blur does sub-frame sampling of the scene, so it takes into account the actual trajectory of particles between frames and deformations of matte objects.
Disadvantages
- The 3ds Max Multi-Pass Motion Blur does sub-frame sampling of the scene, so it has to precalculate, load, light and draw all particles for each pass from scratch, resulting in MUCH longer render times.
- 3ds Max supports only one Multi-Pass effect per camera, so mixing Multi-Pass Depth Of Field and Multi-Pass Motion Blur is not possible.
Warning
Although it is technically possible to have both methods of motion blur enabled at the same time, it is a really bad idea. Krakatoa will NOT check for such combinations, make sure to only enable one of the modes.