The pyro preview ROP is a wrapper for the mantra ROP with specific settings that are optimized for rendering volumes quickly for preview purposes. You can also create a light rig that mimics an environemnt light but renders a lot quicker.
Add Light Rig
Create 6 distant lights for each axis with a master intensity controller.
Remove Light Rig
Delete all nodes in the light rig.
Opens the render control dialog to allow adjustments of the render parameters before rendering.
Valid Frame Range
Controls whether this render node outputs the current frame (Render any frame) or the image sequence specified in the Start/End/Inc parameters (Render Frame Range).
Render Frame Range (strict) will render frames START to END when it is rendered, but will not allow frames outside this range to be rendered at all. Render Frame Range will allow outside frames to be rendered. This is used in conjunction with render dependencies. It also affects the behavior of the 'Override Frame Range' in the Render Control dialog.
Two possible cases where you'd want the strict behavior:
A 60 frame walk cycle written out to a geo, but part of a larger ROP net to render out a larger frame range.
A texture loop from 1-20.
Otherwise, you will usually set this to non-strict.
Render Current Frame
Renders a single frame, based on the value in the playbar or the frame that is requested by a connected output render node.
Render Frame Range
Renders a sequence of frames. If an output render node is connected, this range is generally ignored in favor of frames requested by the output render node.
Render Frame Range (Strict)
Renders a sequence of frames. If an output render node is connected, this range restricts its requested frames to this frame range.
Specifies the range of frames to render (start frame, end frame, and increment). All values may be floating point values. The range is inclusive.
These parameters determine the values of the local variables for the output driver.
For example, if the parameters are set to:
…there will be 4 frames rendered (10.5, 11, 11.5, and 12), so
$NRENDER will have a value of 4.
$N will have the following values at each frame:
Render With Take
The output driver will switch to this take before rendering and then restore the current take when rendering is done.
chs("take") to use this value in other parameters. See the chs expression function for more information.
The path the to camera object to use to render the scene, for example
Override camera resolution
Normally the image resolution is set on the camera object. Turn this on to enable controls that modify or override the camera’s settings.
When Override camera resolution is on, allows you to scale whatever resolution is set on the camera. To completely override the camera’s resolution, choose “User specified resolution”.
When Override camera resolution is on and Resolution scale is “User specified resolution”, lets you set the resolution of the output image, overriding the settings on the camera.
Pixel Aspect Ratio
The pixel aspect ratio represents the width of a pixel divided by the height of a pixel. It is not the aspect ratio of the image (which is determined by the resolution of the image). This parameter does not affect rendering, it is only used to change how images are displayed, by stretching the pixels by this factor.
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:
$F in the file name to insert the frame number. This is necessary when rendering animation. See expressions in file names for more information.
Objects will be output regardless of the state of their display flag
Lights will be output regardless of the value of their dimmer channel
Env Light Intensity
Master intensity control for all lights in the light rig.