UVMap
Brief Description
Applies an UV map to the source image. The UV map indicates for each pixel in output the coordinate of the pixel in the source image that should be used to fill the output pixel. The red channel of the map contains the X coordinate of the source pixel while the green channel of the map contains the Y coordinate. The values of the pixels of the UV map are assumed to be normalized in the range [0,1] where a cooordinate of (1,1) corresponds to the top-right of the source image and a coordinate of (0,0) the bottom-left of the source image.
UV-map are traditionnally generated by 3D renderers so that texturing can be performed at the compositing stage rather by the 3D package itself. For video footage, Autograph offers the UV Map Generator which can generate a UV-map out of video content using motion-vectors analysis.
N.B: When using a map on the UV-map, it is important that the mask is not rendeered with anti-aliasing on the edges of the matte.
Masking of the UV map is binary: either the pixel is moved or it is not, but moving it half the distance only for edge pixels would create artifacts. If you need to improve the quality of the output image, use the Supersmapling parameter, which correctly applies filtering without creating artifacts on the border of the matte.
Controls
| Parameter / Script Name | Type | Default | Function |
|---|---|---|---|
Enabled / enabled | Boolean | On | |
UV Map / uv | Image | - | This effect will read the first 2 channels (i.e: red and green) for the X and Y coordinates respectively |
Red / process_red | Boolean | On | Enable the red channel in output. Otherwise if there's a source the content of the main source is returned instead, else 0 |
Green / process_green | Boolean | On | Enable the green channel in output. Otherwise if there's a source the content of the main source is returned instead, else 0 |
Blue / process_blue | Boolean | On | Enable the blue channel in output. Otherwise if there's a source the content of the main source is returned instead, else 0 |
Alpha / process_alpha | Boolean | On | Enable the alpha channel in output. Otherwise if there's a source the content of the main source is returned instead, else 0 |
Scale / scale | Float 2D | 1, 1 | A scale factor applied to the uv value at each pixel of the uv map |
Offset / offset | Float 2D | 0, 0 | An offset subtracted from the u value at each pixel of the uv map. This is applied after scale |
Wrap U / u_wrap | Choice | Black | How the source image is accessed when the X coordinate is out of bounds - Black - Clamp to edge - Repeat - Mirror |
Wrap V / v_wrap | Choice | Black | How the source image is accessed when the Y coordinate is out of bounds - Black - Clamp to edge - Repeat - Mirror |
Supersampling / supersampling | Choice | x1 | The supersampling factor. Higher means more quality and antialiasing but slower to render - x1 - x2 - x4 - x8 - x16 |
Filter / filter | Choice | Inherit | The antialiasing algorithm used as reconstruction filter. Note that if the uv map contains offset where 2 source pixels do not end up close-by in the output image, any reconstruction filter would produce incorrect results by mixing pixels that are apart in the source image. The only correct way to antialias in this mode is using a supersampling factor below and set filter to Nearest - Inherit: Inherit parent layer filter - None: No interpolation - Box: Box filter - Triangle: Bilinear filter - Hermite: Hermite interpolation filter (smoothstep in glsl) - Hann - Hamming - Blackman - Gaussian - Quadratic - Cubic: General Cubic Filter. Emulates a Gaussian Blurring Filter. This curve is also known as a 'B-Spline' interpolation curve, and is also commonly used for drawing smooth lines through a collection of points. It is also often used for camera and object motions in animations, to produce a smooth flow though the user provided control point - Spline 16 - Spline 36 - Spline 64 - Spline 100 - Spline 144 - Catmull-Rom - Mitchell - Keys - Keys Sharp - Sinc - Jinc - Kaiser - Welch - Parzen - Bohman - Cosine - Bartlett - Lagrange 3 - Lanczos 2 - Lanczos 2 Sharp - Lanczos 3 - Lanczos 3 Sharp - Lanczos 4 - Lanczos 6 |
Mask / mask | Image | - | |
Mix / mix_with_source | Float | 1 | Dissolves between the original image at 0 and the image with the effect applied at 1 |