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Ray-Trace Acceleration: Parameters for the BSP Methods 129
Ray-Trace Acceleration
Parameters
R a y -Tr a ce Accel er a ti on:
Par ameter s for the B SP M ethods
Rendering menu > Render > Render Scene dialog
> Renderer panel > Rendering Algorithms rollout >
Raytrace Acceleration group > Choose BSP or Large BSP
as the R aytrace Acceleration method.
Main toolbar > Render Scene > Render Scene dialog
> Renderer panel > Rendering Algorithms rollout >
Raytrace Acceleration group > Choose BSP or Large BSP
as the R aytrace Acceleration method.
Note: The Processing panel appears only when the
mental ray renderer is the currently active renderer.
When you choose BSP or Large BSP as the
Raytrace Acceleration method on the Rendering
Algorithms rollout (page 3–116),theparameters
described here are displayed. BSP stands for
Binary Space Partitioning. BSP is the default
method. Large BSP is a variant whose par titioning
tree can be swapped in and out of memory, making
it suitable for rendering very large scenes.
Note: If the scene contains too many faces
(triang les) to fit in a t ree of t he size specified by the
Size and Depth parameters, mental ray d isregards
theSizevalueandcreateslargerleafnodes.This
can significantly slow down rendering. To avoid
this problem, increase the value of Depth.
Inter face
Size—Sets the max imum number of faces
(triangles)intheleafofaBSPtree. Increasing
the Size value reduces memory consumption but
increases rendering t ime. Default=10.
Depth—Sets the maximum number of levels
in the BSP tree. Increasing the Depth value
reducesrenderingtime,butincreasesmemory
consumption and preprocessing time. Default=40.
Tip: For large scenes, increasing the Depth value to
50 or more can greatly improve rendering time.
R a y -Tr a ce Accel er a ti on:
Parameters for the Grid Method
Rendering menu > Render > Render Scene dialog
> Renderer panel > Rendering Algorithms rollout >
Raytrace Acceleration group > Choose Grid as the
Raytrace Accelerat ion method.
Main toolbar > Render Scene > Render Scene dialog
> Renderer panel > Rendering Algorithms rollout >
Raytrace Acceleration group > Choose Grid as the
Raytrace Accelerat ion method.
Note: The Processing panel appears only when the
mental ray renderer is the currently ac tive renderer.
When you choose Grid as the Raytrace
Acceleration method on the Rendering Algorithms
rollout (page 3–116),theSize,Depth,and
Resolution parameters are displayed. The grid
method subdivides the scene in to a grid of
"voxels." A voxel is a node in the subdivided scene.
Interfa ce
Size—Sets the max imum number of triangles in
a voxel. If a voxel would contain more triangles,
and the Depth setting per mits it, then the voxel is
subdivided into a subgr id. Default=128.
Depth—Sets the number of recursion levels.
If a voxel grid contains too much detail, it is
subdivided into a subgrid, which adds one level
of recursion. Default=2.