The ampersand symbol means variable overwritten, right? Then what does the uvw mean? UV coordinates? I've checked the intersection position on uv, but they weren't aligned
bao007fei Then what does the uvw mean? UV coordinates?
those are parametric UV coordinates within the primitive (or intrinsic primitive UVs), nothing to do with "uv" attribute
essentially primitive number + parametric uvw will define exact location within the primitive (e.g. on the polygon or within the tetrahedron)
many functions would return such location, intersect(), xyzdist(), uvdist(), Ray SOP, Scatter SOP, ... then you can use such location in primuv() function (or within Attribute Interpolate SOP) to sample an interpolated attribute value at that location
bao007fei Then what does the uvw mean? UV coordinates?
those are parametric UV coordinates within the primitive (or intrinsic primitive UVs), nothing to do with "uv" attribute
essentially primitive number + parametric uvw will define exact location within the primitive (e.g. on the polygon or within the tetrahedron)
many functions would return such location, intersect(), xyzdist(), uvdist(), Ray SOP, Scatter SOP, ... then you can use such location in primuv() function (or within Attribute Interpolate SOP) to sample an interpolated attribute value at that location
Thanks for the explanation. I did some research and finally figured out what you mean about the Primitive Parametric Spaces. Much appreciate.