9

mental ray Volume Shading 95
mental r ay Volume Sha ding
Volumeshadingshadesathree-dimensional
volume, rather than a surface. Typically, volume
shaders provide atmospheric effects such as mist
and fog.
Model rendered with no volume effect
Same model rendered in mist
Mist applied as a camera volume shader; realistic falloff on
Therearetwowaystoassignavolumeshader:
•Toacamera
This effectively makes the entire scene a single
volume.
•Toamaterial
This makes a volume out of objects to which
the material is applied.
Usuallywhenyouassignavolumeshader
to a material, you want to make its surface
transparent so the shading within t he volume is
visible. You can do this with the mental images
T
ransmat shader.
To assign a volume shader to a camera, use the
Render Scene dialog. To assign a volume shader
to a ma terial, use the material’s Volume shader
component. This component is found on the
mental ray Connection rollout (page 2–1461),and
in the mental ray m aterial (page 2–1544) itself. See
the “Procedures” that follow.
Procedures
To apply volume shading to a camera:
1. On the Render toolbar, click Render
Scene.
If the active renderer is not already the mental
ray renderer, go to the Common panel, and
on the Assign Renderer rollout, click the “...”
button for the Production renderer . A Choose
Renderer dia log is displayed. High light “mental
ray Renderer” in the list, and then click OK.
2. ClicktheRenderertabtogototheRenderer
panel. On the Camera Effects rollout, find the
Camera Shaders group, and click Volume.
The Material/Map Browser (page 2–1412) is
displayed.
3. Choose a volume shader from the list in the
Browser, and then click OK.
To appl y volume sha ding to a n object:
1.
Choose Customize > Preferences. Go to the
mental ray panel, and turn on Enable Mental
Ray Ex tensions.
2. On the Render toolbar, click Render
Scene.