C_STMap

The C_STMap node is a GPU accelerated version of Nuke's standard STMap node. The C_STMap node allows you to warp the src input according to the stitch or ppass attached to the map input. C_STMap accepts stitch_map and ppass_map channels in specified layers. The stitch_map UV channels represent the absolute pixel positions of an image normalized between 0 and 1, whereas the ppass_map XYZ channels represent the normalized 3D coordinates of a latlong image ranging between -1 and 1.

Inputs and Controls

Connection Type	Connection Name	Function
Input	map	The input you want to use to warp the source image.
Input	src	The source image to which you want to apply the effect.

Control (UI)	Knob (Scripting)	Default Value	Function
C_STMap Tab
Local GPU	gpuName	N/A	Displays the GPU used for rendering when Use GPU if available is enabled. Local GPU displays Not available when: • Use CPU is selected as the default blink device in the Preferences. • no suitable GPU was found on your system. • it was not possible to create a context for processing on the selected GPU, such as when there is not enough free memory available on the GPU. You can select a different GPU, if available, by navigating to the Preferences and selecting an alternative from the default blink device dropdown. Note: Selecting a different GPU requires you to restart Nuke before the change takes effect.
Use GPU if available	useGPUIfAvailable	enabled	When enabled, rendering occurs on the Local GPU specified, if available, rather than the CPU. Note: Enabling this option with no local GPU allows the script to run on the GPU whenever the script is opened on a machine that does have a GPU available. You should also select this if you wish to render from the command line with the --gpu option. See Nuke 14 Release Notes for more information on the GPUs Nuke supports.
Channels	channels	all	The effect is only applied to these channels. If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.
Map	map	stmap	Sets the map representation to use: • stmap - a two channel UV map. • ppass - a three channel XYZ map.
Map	uv	none	Sets the channels used to calculate the mapping for the src input. The selected layer must contain at least two channels for stmap maps or three channels for ppass maps.
Blur Channel	N/A	disabled	Enables the associated blur channel to the right. Disabling this checkbox is the same as setting the channel to none.
Blur Channel	blur	none	The channel to which the blur effect is added. The value in this channel is added to the sample area to add extra blur or diffusion to the distortion.
Blur Scale	blurScale	1	Scales the blur applied when a Blur Channel is specified.
Filter	filter	Cubic	Select the filtering algorithm to use when remapping pixels from their original positions to new positions. This allows you to avoid problems with image quality, particularly in high contrast areas of the frame (where highly aliased, or jaggy, edges may appear if pixels are not filtered and retain their original values). • Impulse - remapped pixels carry their original values. • Cubic - remapped pixels receive some smoothing. • Keys - remapped pixels receive some smoothing, plus minor sharpening (as shown by the negative -y portions of the curve). • Simon - remapped pixels receive some smoothing, plus medium sharpening (as shown by the negative -y portions of the curve). • Rifman - remapped pixels receive some smoothing, plus significant sharpening (as shown by the negative -y portions of the curve). • Mitchell - remapped pixels receive some smoothing, plus blurring to hide pixelation. • Parzen - remapped pixels receive the greatest smoothing of all filters. • Notch - remapped pixels receive flat smoothing (which tends to hide moire patterns). • Lanczos4, Lanczos6, and Sinc4 - remapped pixels receive sharpening which can be useful for scaling down. Lanczos4 provides the least sharpening and Sinc4 the most.
Black Outside	blackOutside	disabled	When enabled, pixels that fall outside the format are set to black.
Output	mode	Warped Src	Sets the output mode: • Warped src - warps the src input using the map input. • Warped src (inverse) - warps the src input using the inverse of the map input. • Map inverse - writes the inverse of the input map to the channels selected in the Map control. This option doesn't require an src input.
Splatting	splatting	2	Controls the maximum splatting radius used to fill in missing areas of the inverse map. You can increase the radius to fill in large areas, but high values can produce artifacts in the final output. Note: This control is only available when Output is set to Warped src (inverse) or Map inverse.
Interpolate	interpolate	disabled	When enabled, missing data from inverse maps is filled in using a simple interpolation method. When disabled, any missing data is filled in black. Note: This control is only available when Output is set to Warped src (inverse) or Map inverse.
Mask	N/A	disabled	Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.
Mask	maskChannelInput	none	The channel to use as a mask. By default, the roto shapes are limited to the non-black areas of this channel.
Inject	inject	disabled	Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.
Invert	invert_mask	disabled	Inverts the use of the mask channel, so that output is limited to the non-white areas of the mask.
Fringe	fringe	disabled	When enabled, only apply the effect to the edge of the mask. When disabled, the effect is applied to the entire mask.