BLEND NORMALS

[jackassol]

Hello, i added a simple Spline und copied some rectangels on it. (PICTURE 1)

Now i wanted to blend the normals, so that the bottom rectangels always have the direction of the ground (PICTURE 2)

Does anyone know how i can do this?

i posted my hip file aswell

best

spline.hipnc

[f1480187]

Select bottom points, set their normal to {0, 1, 0} with a Wrangle, Point VOP or Point SOP right before copying.

modify_copy_normal.hipnc

[konstantin magnus]

You can blend values (i.e. @N vs. @up) by adding to multiplications with each other:

@N = (@N * (1 - mix) ) + (@up * mix);

mix and 1 - mix are controlling how much influence @N and @up get on each point. So after polyframe you could put this into a wrangle:

float mix = @ptnum / float(@numpt - 1);
vector up = {0, 1, 0};
@N = (@N * (1 - mix) ) + (up * mix);
@N = normalize(@N);

 

blending_normals.hipnc

[konstantin magnus]

You can also use the lerp function instead of line 3.

@N = lerp(@N, up, mix);

 

[jackassol]

wow - really cool - is there also a way to define the falloff? @konstantin magnus

 

[konstantin magnus]

You change the falloff with a ramp by adding

mix = chramp('change_mix', mix);

 and clicking on the little icon appearing right to your code box.