Validate Bidirectional distortion Field Texture

[simco50]

Hi,

The documentation describes being able to provide a bidirectional distortion field but it's not entirely clear what space it should be.

The documentation says this:

Units: the buffer values should be in normalized pixel space [0,1].

But the contents of the buffer describe the relative offset of the UV coordinates after being distorted, so this can be negative? While the code snippet contains this, which contradicts the doc

// The output can be outside of the [0, 1] range
Texture2D[UV] = float4(rg, ba); // needs to be **signed**

Also this:

These should be the same scale as the input MVecs

Is this the scale of the data in the motion vector texture before or after being scaled by sl::Constants::mvecScale?

Given that there are no tools to see what the distortion texture is doing with the other inputs, it's very hard to verify the correctness of the distortion texture. The debug view in the ImGui plugin shows that all the inputs (eg. Motion/Depth) are unaffected by the distortion texture. So again, hard to validate.

Any futher details would be helpful.

Thanks, Simon