Accessing Parametric UV's on a surface....

[Sevro]

Is there a way to access the parametric uv's on a surface?  I can get the assigned uv's, but not sure how I can access the intrinsic/implicit uv's for a shape?  

 

[konstantin magnus]

The VEX functions xyzdist() or intersect() return primitive numbers along with intrinsic UV locations. Interpolated attribute values can then be obtained using primuv().

Documentation:
https://www.sidefx.com/docs/houdini/vex/functions/xyzdist.html
https://www.sidefx.com/docs/houdini/vex/functions/intersect.html
https://www.sidefx.com/docs/houdini/vex/functions/primuv.html

Examples:
Eg. transfer normals from the closest surface position of the second input:

int prim;
vector uvw;
float dist = xyzdist(1, v@P, prim, uvw);
vector nml = primuv(1, 'N', prim, uvw);

Eg. transfer color attribute from ray intersection with another surface:

float range = 1000.0;
vector pos = v@P + v@N * 1e-3;
vector dir = v@N * range;

vector pos_hit;
vector uvw_hit;
int prim_hit = intersect(1, pos, dir, pos_hit, uvw_hit);

v@Cd = primuv(1, 'Cd', prim_hit, uvw_hit);