I have a cylinder and want to distribute some points on it. One side needs to have more points that the other. Then I copy some objects onto these points. In some parts of the cylinder the objects need to be larger than in the others. I thought I would use ramps but I am struggling to find inromation/understand how to wire them properly to the appropriate parameters…

Thank you for the advice,

Anna

Basically, this boils down to setting up (geometry) attribute values the way you want them, and then driving the scatter and size of your copies using the attribute values. See the attached file.

Some highlights:
- AttribCreate SOP -> the lets you create an attribute, ie. custom value per point, or per primitive
- You can add a custom ramp parameter to the AttribCreate SOP to control how the values are created. I've use the chramp() expression here to evaluate the ramp along with the $BBX local variable. $BBX ranges from 0 to 1 within the bounding box of object in the X direction.
- Paint SOP -> You can also paint an attribute value that you've created using AttribCreate using its Override Color parameter. In the example, I use a Paint SOP to paint the size attribute. Later on, I also use it to visualize the area attribute too.
- Scatter SOP -> You can give a primitive attribute to control how much to scatter.
- Copy SOP -> we can propagate the painted attribute value over to the copies via the “copy stamping” concept. The stamp() expressing is used to get at the size attribute in the example.

Thank you very much! Most kind. I shall go and study it now…