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120 Chapter 17: Rendering
Dia gnostics R ollout (mental r ay
Renderer)
Rendering menu > Render > Render Scene dialog >
Processing panel > Diagnostics rollout
Main toolbar > Render Scene > Render Scene dialog >
Processing panel > Diagnostics rollout
Note: The Processing panel appears o nly when the
mental ray renderer is the currently active renderer.
ThetoolsontheDiagnosticsrolloutcanhelp
you understand why the mental ray renderer is
behaving in a certain way. The Sampling Rate
tool, in part icular, can help explain the renderer’s
perfor mance.
Each of these tools generates a rendering that
is not a photorealistic view, but a schematic
representation of the functionality you hav e
chosen to analyze.
Inter face
Enable—When on, the renderer renders t he
graphic representation for the tool you have
chosen.
Sampling R ate—When chosen, renders an image
that shows where samples were collected during
rendering; see
Sampling (mental ray Renderer)
(page 3–1099)
. This can help you adjust the
cont rast and other sampling parameters.
Coordi nate S pace—Renders an image that shows
thecoordinatespaceofobjects,theworld,or
camera.
•
Object—Shows local coordinates (UVW). Each
object has its own coordinate space.
•
Worl d —Shows world coordinates (XYZ). The
same coordinate system applies to all objects.
•
Cam era—Shows camera coordinates, which
appear as a rectangular grid superimposed on
the view.
Size—Sets the size of the grid. Default=1.0.
Tip: To avoid busy moiré patterns in the grid,
increase the value of Size.
Photon—Renders the effect of a photon map in the
screen. This requires that a photon map b e present
(to render caustics or global illumination). If no
photon map is present, the Photon rendering looks
just like the nondiagnostic rendering of the scene:
the mental ray renderer first renders the shaded
scene, then replaces it with the pseudocolor image.
•
Density —Renders the photon map as it is
projected into the scene. High density is
displayedinred,andlowervaluesrenderin
increasingly cooler colors.
•
Irradiance—Similar to the Density rendering,
but shades the photons based on their
irradiance. The maximum irr adiance is
rendered in red, and lower values render in
increasingly cooler colors.
BSP—Renders a visualization of the parameters
usedbythetreeinthe
BSP ray-trace acceleration
method (page 3–125)
. If a message from the
renderer reports excessively large depth or size
values, or if rendering se ems unusually slow, this
can help you locate the problem.
•
Depth—Shows the depth of the tree, with top
faces in bright red, and increasingly deep faces
in increasingly cool colors.
•
Size—Shows the size of leaves in the tree, with
differently sized leaves indicated by different
colors.