On this page | |
Since | 18.0 |
Overview
-
A UsdRenderSettings prim holds global render settings for rendering the scene, as well as a list of
UsdRenderProduct
prims representing the rendered files/buffers, and which purposes should be rendered. -
Render settings prims must be somewhere under
/Render
in the scene graph tree.
Creating vs. editing prims
This node belongs to a class of nodes that create or edit USD prims directly. These nodes operate in Create mode or Edit mode. This is controlled by a Create primitives checkbox or a Create/Edit popup menu. In create mode, the node creates new prims. In edit mode, the node changes the attributes on an existing prim.
Parameters that correspond to a USD attribute have a pop-up menu to the left that controls how the node authors the attribute.
Pop-up menu item |
Meaning |
---|---|
Set or Create |
Sets the attribute to the given value, whether it previously existed or not. |
Set If Exists |
Only set the attribute to the given value if it previously existed. Use this mode to make sure an attribute is only set on primitives of the correct type. For example, only |
Block |
Makes the attribute appear to not exist, so it takes on its default value. (If the attribute doesn’t already exist on the prim, this does nothing.) |
Do Nothing |
Ignore this parameter, don’t create or change the attribute in any way. |
Parameters
Action
Whether this node should create new prims, or edit existing prims.
Primitive Path
In create mode, this lets you control where in the scene graph to create the prim(s).
The default is usually /$OS
. This creates a primitive at the root level with the same name as the node (for example, /tube1
). This is a useful default for preventing naming conflicts, but terrible for organization. You should try to remember to change the Primitive path to a better value when you create prims.
For example, instead of naming models after the node that created them, you might want to name them after the geometry inside, and organize them under a /Models
branch.
The "Create primitives" section contains basic controls for how to create the new prim(s).
Primitives
In edit mode, the node has a Primitive pattern parameter. This lets you specify the prim(s) the node should operate on. You can click the select button beside the text box to select the primitives from the scene graph tree. You can also use primitive patterns for advanced matching, including matching all prims in a collection.
Initialize Parameters For Edit
In edit mode, changes the state of all control menu parameters to Do Nothing
, so that this node will not apply any changes. Also grabs the current values of each property from the first Primitives match, and sets the values of the corresponding parameters to match. This means that changing any parameter’s control menu to Set or Create
mode will set the property to its current value, making it easier to apply changes to an existing value rather than setting a brand new value.
Create Primitives
This section only appears when the node is creating primitives.
For example:
-
If you want to create a new cube primitive at
/world/objects/cube1
on an empty stage: Set Primitive Specifier to "Define", and the Parent Primitive Type to "Xform". -
If you want to override the radius of a sphere at
/world/objects/sphere1
: Set Primitive Specifier to "Over", and the Parent Primitive Type to None. This makes sure the primitive types of any existing ancestor prims are not be modified by this node.
Primitive Count
The number of primitives to create.
Primitive Kind
Set all created prims to have this kind.
Parent Primitive Type
If any parents of a path in Primitive paths do not exist, this node will automatically create them. In this case, it will create parent nodes of this type.
Primitive Specifier
The USD operator to use when creating the new prims.
Define
Authors a completely new prim. Use this if you want to create a brand new prim or replace an existing prim.
Over
Authors an override of an existing prim. Attributes not explicitly authored on this prim will get their values from the existing prim on the lower layer.
Class
Define a primitive class. This is usually not necessary unless you are doing deep USD magic.
Standard
Products
A list of paths to UsdRenderProduct prims, representing the rendered outputs. If you don’t specify any explicit products, the renderer should by default output an RGB image using the render settings on this node, to a default display or image name.
Included Purposes
A list of purpose tokens (such as render
(final render), proxy
, and guide
, from UsdGeomImageable
). Only geometry with its purpose set to one of these tokens will be sent to the renderer. The default
purpose is the purpose for all geometry that doesn’t have an explicitly set purpose, so you will usually want to include it.
(This cannot be specified per-product because it is a statement of which geometry is present.)
Material Binding Purposes
A list of material purpose tokens to consider when resolving material bindings.
Camera
Path to a USD camera (UsdGeomCamera
) prim to render the scene from.
Resolution
The horizontal and vertical size of the output image, in pixels.
Instantaneous Shutter
Override the camera’s Shutter close parameter to be equal to its Shutter open time, to produce a zero-width shutter interval. This is a convenient way to disable motion blur.
Aspect Ratio Conform Policy
What to do if the aspect ratio of the output image (Resolution width divided by height) doesn’t match the aspect ratio of the camera aperture (controlled by attributes on the camera). This allows a standard renderer to do something reasonable when you switch between cameras.
Expand Aperture
If necessary, expand the camera aperture to match the image.
Crop Aperture
If necessary, crop the camera aperture to match the image.
Adjust Aperture Width
If necessary, change the camera aperture width to match the image.
Adjust Aperture Height
If necessary, change the camera aperture height to match the image.
Adjust Pixel Aspect Ratio
Change the aspect ratio of the image to match the camera.
Data Window NDC
Directs the renderer to only render within this window of the entire output image. The rectangle is specified in as minX, minY, maxX, maxY
, in a normalized range 0
to 1
. Coordinates 0, 0
are the bottom left and 1, 1
are the top right. The default window 0, 0, 1, 1
covers the entire image (that is, is not cropped).
You can use this window to temporarily crop the render to a smaller region, for testing purposes.
You can also specify negative values and/or values greater than 1 to reveal overscan data.
Pixels are only rendered if they are fully inside the window.
The normalized coordinates map to the image after any adjustments by the Aspect ratio conform policy.
Pixel Aspect Ratio
The aspect ratio (width/height) of image pixels (not the image itself).
The default is 1.0
, indicating square pixels.
Karma
Show Alfred Progress
As rendering progresses, print out progress using the Alfred progress format. For multi-frame renders, this progress will be cumulative across frames (i.e. if there are 4 frames, percent complete will be 25% after the first frame finishes).
IPR Inc Random
When rendering to the Solaris viewport, this causes each render to start with a new random seed.
IPR Bucket Size
The initial bucket size for IPR rendering.
IPR Reserve Threads
When rendering in IPR mode, reserve this number of threads for other Houdini tasks.
Cache Limit
Whether to use a fixed size cache (karma:global:cachesize
) or whether to use a proportion of physical memory (karma:global:cacheratio
)
Cache Memory Ratio
The proportion of physical memory Karma will use for its unified cache.
For example, with the default vm_cacheratio
of 0.25
and 16 Gb of
physical memory, Karma will use 4 Gb for its unified cache.
The unified cache stores dynamic, unloadable data used by the render including the following:
-
2D
.rat
texture tiles -
3D
.i3d
texture tiles -
3D
.pc
point cloud pages (when not preloaded into memory)
Note: This value is only used for off-line rendering, not IPR.
Cache Size (MB)
An explicit memory limit for the unified shading cache. This is deprecated in favor of using the Cache Memory Ratio.
Note: This value is only used for off-line rendering, not IPR.
Pixel Samples
The number of ray-samples sent through each pixel. More samples will result in a less noisy image.
Ray Bias
The ray-bias used for secondary rays.
Screendoor Limit
Disable Lighting
Disable all lighting and material evaluation, using only the display color to shade primitives.
Headlight AO Samples
When rendering in headlight mode, perform this many ambient occlusion samples per shade.
Headlight AO Distance
When rendering in headlight mode with ambient occlusion shading, this distance is used for occlusion testing. Smaller values will result in faster, but less accurate shading.
Headlight Fog Color
The color of the depthcue fog for disabled lighting.
Light Sampling Mode
Whether Karma should perform uniform sampling of lights or whether rendering should use the light tree. The light tree can be significantly faster for scenes that have large numbers of lights.
Light Sampling Quality
This is a global control to improve sampling quality for all lights. This acts as a multiplier on the individual light quality controls. Increasing the quality will improve direct light sampling as well as shadows/occlusion.
Color Limit
The maximum value a shading sample is allowed to contribute to an LPE image plane to reduce appearance of "fireflies" caused by undersampling of extremely bright light sources. Note that reducing this value can result in an overall reduction in the amount of light in your scene
Camera
The rendering camera.
Offscreen Quality
This parameter controls the shading quality scale factor for geometry that is not directly visible to the camera. For geometry that is outside the field of view (ie. visible only to secondary rays), karma will smoothly reduce the shading quality based on the angle between the geometry and the edge of the viewing frustum. Smaller values can increase performance particularly in scenes where the camera is within the displacement bound of nearby geometry, where it permits the hidden primitives to be diced more coarsely than those that are directly visible.
Image Filters
Image filters post-process the filtered pixels to produce the final image.
This parameter specifies a list of filters. These filters are specified as a JSON list.
Sample Filter
Sample filters are used to modify samples before they are sent to pixel filters.
This parameter specifies a list of filters. These filters are specified as a JSON list.
Pixel Oracle
When rendering, a Pixel Oracle tells karma which pixels need additional sampling and which pixels are converged.
This parameter tells karma which oracle to use.
Random Seed
This is the random seed to use for the render.
Abort Missing Texture
Enabling this option will cause karma to abort the render with an error if it encounters a missing texture map.
Export Components
A whitespace-separated list of shading component names that will be computed for export. If you have defined new component labels in your materials, these can be added to the list so that they are exported for per-component export planes. If you are not using some components, remove them from the list to improve render efficiency.
PBR light exports assume that this list is complete - that is, all components created by shaders are listed. If there are unlisted components, light exports may be missing illumination from these components.