Render scenes with Paint Effects strokes

Paint Effects strokes render seamlessly with the rest of your scenes. They are affected by motion blur, depth of field, and fog.

Note: Paint Effects uses the depth buffer generated by the scanline render to determine occlusion.

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 VisibleDepth 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 the Paint Effects separately and composite.
• Convert your Paint Effects strokes to polygonal meshes, including construction history, using Modify > Convert > Paint Effects to Polygons. See Convert Paint Effects to geometry.
• For problems with Closest Visible, try adjusting its Threshold value to an approximate value of 0.3.

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

1. Set up your lights, render camera, render options, and Paint Effects render options. For details, see Prepare to render scenes with Paint Effects,
2. Render the scene as you would any Maya scene.
   • For information on rendering a single frame, see Render a single frame.
   • For information on rendering an animation, see Batch render a still or animation.

Note: Paint Effects renders are always multiprocessed. To turn off multiprocessing, do the following:

• Exit Maya (or stop your batch render).
• Set the MAYA_PAINT_EFFECTS_THREADS environment variable to a value between 1 and 3, for the number of processors you want to use.
• Start Maya (or restart your batch render).
• Re-render your scene.

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.

To create a composite

1. Render the scene or animation without Paint Effects strokes as follows:
   • Select Windows > Rendering Editors > Render Settings.
   • If you are compositing an animation, beside Frame/Animation Ext, select name.#.ext.
   • Image formats which are.iff or.rla will have embedded depth information. Other formats will create a separate .iff file containing the depth information. This depth file would normally be written to the projects depth directory. For this example render the images as .iff.
   • In the File Output section, turn on Depth Channel (Z Depth) beside Channels.
   • In the Paint Effects Rendering Options section, turn off Enable Stroke Rendering.
   • Render the scene or animation (for example, rainyday). For details, see Render a single frame or Batch render a still or animation.
2. Save the scene using a different file name to ensure that the rendered images do not overwrite each other (for example, rainydaywithstrokes).
3. Render the strokes with the scene as follows:
   • Make sure the camera and the lights are set up to match the camera and lights in step #1.
   • Select Windows > Rendering Editors > Render Settings.
   • If you are compositing an animation, beside Frame/Animation Ext, select name.#.ext.
   • In the Paint Effects Rendering Options section, turn on Enable Stroke RenderingandOnly Render Strokes.
   • Beside Read This Depth File, type the location and name of the depth file for the image you rendered in step #1. Make sure it is an absolute path name (for example, /h/pearce/rainyday.iff or c:\pearce\rainyday.iff).

   If you are rendering an animation, use the file name format name.#.iff (for example, rainyday.#.iff).

   • Render the scene or animation. For details, see Render a single frame or Batch render a still or animation.

   Output images are created and named using the format name.#.iff (for example rainydaywithstrokes.5.iff).