RESOLVED:Transform Edge Artifacts (Build 2018.24410 / Win 7)

When using the Transform TOP to offset an image, its edges gets strange artifacts, which even change when transform is animated.

Using 32Bit precision doesn’t help to avoid them… Win 7 / Build 2018.24410
Transform Edge Artifacts.toe (4.21 KB)

The artifacts here are because the lookup texture is interpolating pixels.

If you set Input Smoothness = Nearest Pixel on both transform1 and remap1 you’ll see a nice result artifact free. However, then you’ll the low resolution of your lookup texture come through giving you some pixelation, so you’ll need to up the resolution on your Ramp TOPs creating the lookup texture to the same resolution as your image ie. 1280x720

Thanks for the insight… But why the interpolation happens in the first place, since the image should wrap around mathematically precise?

For the Transform TOP you are offsetting the image by fractional pixels. So in the new map that is created the boundary pixels are getting created using a blend of pixels on the left and right or bottom and top pixels of the image. So you are getting a few pixels that are a blend between 1->0, causing those artifacts.

For the Remap TOP you are sampling a 1280x720 grid onto a 256x256 grid, so none of those samples are going to be dead-center on a pixel either and they’ll get interpolated as well.

Ok, thanks for the explanation. I always thought that border pixels are locked and not part of the interpolation… good to know!