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126 Chapter 4: Obj ect Properties
When off, the light’s direct il lumination is
used only when you render the scene. This is
comparable to the Render Direct Illumination
option.
for more information about the Re-Use Direct
Illumination and Render Direct Illumination
options, see Rendering P ar ameters Rollout
(Radiosity) (page 3–71). In general, re-using
direct illumination stored in the radiosity mesh
improves render time, but shadows appear coarse
and inaccurate unless the mesh is very fine.
Rendering direct illumination an d shadows (using
the radiosity mesh to prov ide only indirect light)
takes more time but gives you a more finished and
accurate image.
menta l r ay Pa nel (Obj ect
Pr oper t ies Dia log)
Edit menu > Object Properties > Object Properties dialog
>mentalraypanel
Select object or objects. > Right-click. > Transform
(lower-right) quadrant of the quad menu > Properties >
Object Properties dialog > mental ray panel
Layer manager > Click the icon next to an object’s name.
> Object Properties dialog > mental ray panel
This panel of the Object Properties dialog supports
mental ray render ing; specifically, the indirect
illumination features caustics (page 3–92) and
global illumination (page 3–93).Theycontrol
whether objects generate or receive caustics or
global illumination.
These settings are ignored where they aren’t
appropriate. F or example, lights can be set to
generate caustics, but for a light, the Receive
Causticssettinghasnoeffect,aslightsaren’t
renderable. Similarly, these settings have no
meaning for cameras.
Also available on this panel are controls for setting
displacement p ar a meters on a per-object basis.
Interfa ce
Thementalraypanelcontainsparametersforthementalray
renderer.
Indirect Illumination group
Generate Caustics—When on, the object can
generate caustics. (For this to happen, Caustics
must also be enabled using the Render Scene
dialog’s Caustics And Global Illumination rollout
(page 3–106).) When off, the object does not
generate caustics. D efault=off.
Receive Caustics—When on, the object can receive
caustics. That is, caustic effects are cast onto
this object. (For this to happen, Caustics must
also be enabled using the Caustics And Global
Illumination rollout.) When off, the object does
not receive caustics. Default=on.
Genera te Global I llumina tion—When on, the object
can generate global illumination. (For this to
happen, Global Illumination must also be enabled
using the Caustics And Global Illumination
rollout.) When off, the object does not generate
global illumination. Default=off.
Receive Global Illumination—When on, the object
can receive global illumination. T hat is, reflected
lightiscastontothisobject.(Forthistohappen,
Global must also be enabled using the Caustics
And Global Illumination rollout.) When off,
theobjectdoesnotreceiveglobalillumination.
Default=on.