STMap node — Natron 2.5.0 documentation

# STMap node

This documentation is for version 2.0 of STMap (net.sf.openfx.STMap).

## Description

Move pixels around an image, based on a UVmap.

The U and V channels give, for each pixel in the destination image, the normalized position of the pixel where the color is taken. (0,0) is the bottom left corner of the input image, while (1,1) is the top right corner. This plugin concatenates transforms upstream, so that if the nodes upstream output a 3x3 transform (e.g. Transform, CornerPin, Dot, NoOp, Switch), the original image is sampled only once.

This plugin concatenates transforms upstream.

## Inputs

Input | Description | Optional
--- | --- | ---
UV |  | No
Source |  | No
Mask |  | Yes

## Controls

Parameter / script name | Type | Default | Function
--- | --- | --- | ---
U Channel / `channelU` | Choice | Color.R | Input U channel from UV. Color.R (uk.co.thefoundry.OfxImagePlaneColour.R): R channel from input UV Color.G (uk.co.thefoundry.OfxImagePlaneColour.G): G channel from input UV Color.B (uk.co.thefoundry.OfxImagePlaneColour.B): B channel from input UV Color.A (uk.co.thefoundry.OfxImagePlaneColour.A): A channel from input UV 0: 0 constant channel 1: 1 constant channel
V Channel / `channelV` | Choice | Color.G | Input V channel from UV. Color.R (uk.co.thefoundry.OfxImagePlaneColour.R): R channel from input UV Color.G (uk.co.thefoundry.OfxImagePlaneColour.G): G channel from input UV Color.B (uk.co.thefoundry.OfxImagePlaneColour.B): B channel from input UV Color.A (uk.co.thefoundry.OfxImagePlaneColour.A): A channel from input UV 0: 0 constant channel 1: 1 constant channel
Alpha Channel / `channelA` | Choice | Color.A | Input Alpha channel from UV. The Output alpha is multiplied by this value. If “Unpremult UV” is checked, the UV values are divided by alpha. Color.R (uk.co.thefoundry.OfxImagePlaneColour.R): R channel from input UV Color.G (uk.co.thefoundry.OfxImagePlaneColour.G): G channel from input UV Color.B (uk.co.thefoundry.OfxImagePlaneColour.B): B channel from input UV Color.A (uk.co.thefoundry.OfxImagePlaneColour.A): A channel from input UV 0: 0 constant channel 1: 1 constant channel
Unpremult UV / `unpremultUV` | Boolean | Off | Unpremult UV by Alpha from UV. Check if UV values look small for small values of Alpha (3D software sometimes write premultiplied UV values).
UV Offset / `uvOffset` | Double | U: 0 V: 0 | Offset to subtract from the U and V channel (useful if these were stored in a file that cannot handle negative numbers)
UV Scale / `uvScale` | Double | U: 1 V: 1 | Scale factor to apply to the U and V channel after subtracting the offset (useful if these were stored in a file that can only store integer values)
U Wrap Mode / `wrapU` | Choice | Clamp | Wrap mode for U coordinate. Clamp (clamp): Texture edges are black (if blackOutside is checked) or stretched indefinitely. Repeat (repeat): Texture is repeated. Mirror (mirror): Texture is mirrored alternatively.
V Wrap Mode / `wrapV` | Choice | Clamp | Wrap mode for V coordinate. Clamp (clamp): Texture edges are black (if blackOutside is checked) or stretched indefinitely. Repeat (repeat): Texture is repeated. Mirror (mirror): Texture is mirrored alternatively.
Filter / `filter` | Choice | Cubic | Filtering algorithm - some filters may produce values outside of the initial range (*) or modify the values even if there is no movement (+). Impulse (impulse): (nearest neighbor / box) Use original values. Box (box): Integrate the source image over the bounding box of the back-transformed pixel. Bilinear (bilinear): (tent / triangle) Bilinear interpolation between original values. Cubic (cubic): (cubic spline) Some smoothing. Keys (keys): (Catmull-Rom / Hermite spline) Some smoothing, plus minor sharpening (*). Simon (simon): Some smoothing, plus medium sharpening (*). Rifman (rifman): Some smoothing, plus significant sharpening (*). Mitchell (mitchell): Some smoothing, plus blurring to hide pixelation (*)(+). Parzen (parzen): (cubic B-spline) Greatest smoothing of all filters (+). Notch (notch): Flat smoothing (which tends to hide moire’ patterns) (+).
Clamp / `clamp` | Boolean | Off | Clamp filter output within the original range - useful to avoid negative values in mattes
Black outside / `black_outside` | Boolean | On | Fill the area outside the source image with black
Use Source RoD / `useRoD` | Boolean | Off | Use the region of definition of the source as the source format.
(Un)premult / `premult` | Boolean | Off | Divide the image by the alpha channel before processing, and re-multiply it afterwards. Use if the input images are premultiplied.
Invert Mask / `maskInvert` | Boolean | Off | When checked, the effect is fully applied where the mask is 0.
Mix / `mix` | Double | 1 | Mix factor between the original and the transformed image.