Following surface tangent, pointing to a target, issue..!

[Masoud]

Hi guys,

 

I need to create a vector attribute, where all the vectors are aligned along the tangent of the surface, while also pointing toward a specified target point.

I believe that combining the Tangent-field SOP with the Normal vector attribute should provide the solution, but I'm not sure how to properly blend them together!

vector target_pos =  point(0, "P", 66);

vector normal = normalize(@N);

vector tangent = v@field1;

vector dir_to_target = normalize(target_pos - @P);

v@FinalVect = ?

 

 

Thanks for helping.

TangetntField_01.hip

[Aizatulin]

Hi

you can project the direction onto the surface using the Y-direction for example.

TangetntField_01_mod.hipnc

[haggi]

Or without a double intersect call:

vector A =  point(0, "P", 66);
vector B = normalize(A-v@P);
vector C = v@P + B * .1;// 0.1 to avoid overshooting
int prim;
vector primuv;
xyzdist(0, C, prim, primuv);
vector surfaceP;
prim_attribute(0, surfaceP, "P", prim, primuv);
v@field1 = normalize(surfaceP-v@P);

 

[satoru]

I usually do it like this.

gradient.hiplc

Edited March 28 by satoru

[haggi]

Houdini has sooo many cool nodes, thanks for sharing the file. I learn new things every day.