Paint Effects strokes render seamlessly with the rest of your scenes. They are affected by motion blur, depth of field, and fog.
For rendered effects where multiple surfaces are visible within a single pixel (such as transparency, antialiased edges, motion blur, light fog, and volume densities) this causes problems, as there is only one depth value and one color per pixel to composite Paint Effects into.
You can affect how the renderer decides how to reduce multiple depth values visible within a pixel to the single output depth value using the camera Depth Type attribute.
If you use Closest Visible Depth type, the renderer picks the surface nearest the camera within the pixel and transparent surfaces or motion blurred streaks totally obscure any Paint Effects elements behind them. If you use Furthest Visible instead, then Paint Effects elements lying behind these elements will punch through as if they were totally in front.
The best solutions in these situations are as follows:
Render a scene with Paint Effects strokes
You can render a scene either from within Maya or from a Linux shell, or DOS window, or Terminal. Before rendering, close all applications (including Maya, if you are rendering from a Linux shell, or DOS window, or Terminal) to maximize the amount of memory available for rendering.
To render a scene with Paint Effects strokes
After rendering an image or an animation, you will want to view the result. For information, see “Viewing Rendered Images” in the Rendering guide.
Create a composite of Paint Effects strokes and your scene
You can render Paint Effects strokes independently of the rest of your scene, then composite the resulting images.
If you are rendering an animation, use the file name format name.#.iff (for example, rainyday.#.iff).
Output images are created and named using the format name.#.iff (for example rainydaywithstrokes.5.iff).