4d8f9bb88e
Regression from #131134. The shader still reads `vel.obj.ofs[STEP_NEXT]` even when in the viewport. - Ensure that `vel.obj.ofs[STEP_NEXT]` points to a valid memory location even if the computed value is still wrong. - Ensure that the viewport always uses a 2 channel vector_tx and all texture reads are always swizzled. This also seems to fix the motion vector pass for the realtime compositor. Pull Request: https://projects.blender.org/blender/blender/pulls/131445