Since | 18.0 |
The Karma Render Properties LOP creates render vars, a
render product and a
render settings primitive, configured for Karma.
Parameters
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.
Screendoor Limit
Images
Output picture
The image or device where the resulting image will be rendered. You can set this value to ip
which renders the image in MPlay, or you can save it to an image. The following image types are supported: .pic
, .tif
, .sgi
, .pic.gz
, .rat
, .jpg
, .cin
, .rta
, .bmp
, .tga
, .rad
, .exr
, and .png
.
Include $F
in the file name to insert the frame number. This is necessary when rendering animation. See expressions in file names for more information.
Output
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
Image Filters
Image filters post-process the filtered pixels to produce the final image.
Optix Denoiser
Adds the NVIDIA Optix Denoiser as an image filter.
Use Albedo
???
Use N Input
???
Use Gl Input
???
OCIO
OCIO image filters can be added to various render vars/image planes.
Enable
Enables the OCIO image filter defined below.
Planes
Specify the render var names to which the OCIO image filter will be applied.
Output Space
Specify the OCIO color output space the image filter will apply.
Input Space
???
Looks
???
Sample Filters
Sample filters are used to modify samples before they are sent to pixel filters.
Color Limits
Color Limits can be applied to a number of render vars individually.
Enable
Enables the color limit sample filter defined below.
Planes
Specify the render var names to which the color limit sample filter will be applied.
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
Render Vars (AOVs)
Render vars, otherwise known as AOVs (arbitrary output variables) or additional image planes, can be specified here. By default the beauty
, diffuse
, glossy reflection
, volume
, depth
, UV
and normal
render vars are enabled and will write to their respective channels.
Additional render vars can be defined on the node or passed in as render var primitives through the second input for convenience.
Import Secondary Input Render Vars
Enables additional render var primitives passed in through the nodes' second input. When disabled, these won’t be merged into the stage.
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.
Diffuse Components
A space-separated list of component types that will behave like diffuse bounces. This will affect which reflection scope is used based on the ray type and also which bounce limit to use. Uncategorized component types are assumed to be reflections.
Refract Components
A space-separated list of component types that will behave like refract bounces. This will affect which reflection scope is used based on the ray type and also which bounce limit to use. Uncategorized component types are assumed to be reflections.
Volume Components
A space-separated list of component types that will behave like volume bounces. This will affect which reflection scope is used based on the ray type and also which bounce limit to use. Uncategorized component types are assumed to be reflections.
SSS Components
A space-separated list of component types that will behave like subsurface scatter bounces. This will affect which reflection scope is used based on the ray type and also which bounce limit to use. Uncategorized component types are assumed to be reflections.
LPE (Light Path Expressions)
Standard light path expression render vars
Beauty
Add the beauty output as an RGBA channel labelled C
.
Precision
Select between 16 and 32 bit precision.
Beauty Unshadowed
Add the unoccluded (unshadowed) beauty output as an RGB channel labelled beautyunshadowed
- defined as unoccluded;C.*
.
Diffuse
Add the diffuse surface reflection component as an RGB channel labelled diffuse
- defined as C<RD>L
.
Diffuse Unshadowed
Add the unoccluded (unshadowed) diffuse surface reflection component as an RGB channel labelled diffuseunshadowed
- defined as unoccluded;C<RD>L
.
Indirect Diffuse
Add the indirect diffuse surface reflection component as an RGB channel labelled indirectdiffuse
- defined as C<RD>.+L
.
Glossy Reflection
Add the glossy reflection component as an RGB channel labelled glossyreflection
- defined as C<RG>L
.
Indirect Glossy Reflection
Add the indirect glossy reflection component as an RGB channel labelled indirectglossyreflection
- defined as C<RG>.+L
.
Glossy Transmission
Add the glossy transmission component as an RGB channel labelled glossytransmission
- defined as C<TG>.*
.
Visible Lights
Add the visible lights component as an RGB channel labelled visiblelights
- defined as CL
.
Emission
Add the emission component as an RGB channel labelled emission
- defined as CO
.
Indirect Emission
Add the indirect emission component as an RGB channel labelled indirectemission
- defined as C.+O
.
Volume
Add the volume component as an RGB channel labelled volume
- defined as CVL
.
Indirect Volume
Add the indirect volume component as an RGB channel labelled indirectvolume
- defined as CV.+L
.
BSDF Labelled coat
Add the coat component as an RGB channel labelled coat
- defined as C<...'coat'>.*
.
BSDF Labelled sss
Add the sss component as an RGB channel labelled sss
- defined as C<...'sss'>.*
.
Ray
Ray Origin (P)
Add the ray origin render var as a Float3 channel labelled rayorigin
.
Ray Direction (D)
Add the ray direction render var as a Float3 channel labelled raydirection
.
Time (Shutter Time)
Add the shutter time render var as a Float channel labelled time
.
Near (Near Bias)
Add the near bias render var as a Float channel labelled near
.
Far (Max Distance)
Add the max distance render var as a Float channel labelled far
.
Mask (Intersection Mask)
Add the mask render var (alpha) as a Float channel labelled mask
.
Contribution
Add the ray contribution render var as a Float channel labelled contribution
.
P (World Space)
Add the world space position render var as a Float3 channel labelled P
.
Depth (Camera Space)
Add the depth render var as a Float channel labelled depth
.
Hitstack
Add the ray hit stack render var as a Float channel labelled hitstack
.
Element (Raw Id)
Add the element id render var as a Float channel labelled element
.
Prim Id
Add the primitive identifier render var as a Float channel labelled primid
.
UV
Add the primitive hit UV render var as a Float3 channel labelled UV
.
Hit Dist
Add the primitive hit distance render var as a Float channel labelled hitdist
.
dPdz
Add the dPdz (Z-depth delta for the current microvolume) render var as a Float channel labelled dPdz
.
N (Smooth Normal)
Add the primitive hit normal render var as a Float3 channel labelled N
.
Ng (Geometric Normal)
Add the primitive geometric normal render var as a Float3 channel labelled Ng
.
Flags
Add the ray flags render var as a Float channel labelled flags
.
Extra Render Vars
Additional render vars can be added on the node directly.
Render Var
Rendering
Sampling
Pixel Samples
The number of ray-samples sent through each pixel. More samples will result in a less noisy image.
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.
Random Seed
This is the random seed to use for the render.
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.
Minimum Samples
???
Plane
???
Variance Threshold
???
Headlight
Force Headlight Shading
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.
Shading
Ray Bias
The ray-bias used for secondary rays.
Render
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.
Dicing
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.
Statistics
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).
Driver
Abort Missing Texture
Enabling this option will cause karma to abort the render with an error if it encounters a missing texture map.
See also |