[QUESTION] Possible for a For Each Loop to boolean every time on the geometry left from the previous iteration?

[neblina]

Hello everyone,

how would one accomplish something like this? 

Given a sphere with many points scattered on its surface, how should a For Each Point Loop be setup to have every iteration boolean a cube out of the surface of the sphere, but always use the resulting geometry of the first iteration for the next boolean? 

The expected result is a sphere with many holes. What I get instead is a sphere that has been indeed booleanized, but since all results 'overlap' without Single Pass checked, it still looks like a full sphere (see example attached). This is a simplified version of one issue I'm having with a project.

I hope I could explain this properly. Has anyone an idea? 

Thanks in advance! 

 

[neblina]

Oh nice, I got it working!

Attached the solution. I placed another Meta Import Node, set it to Fetch Feedback and append after the Sphere before getting it inside the loop. The Block End was then set to Feedback Each Iteration. 

[djiki]

Is there some special reason for doing boolean in each iteration?  If you only need holes on your sphere there is no need to use FOR loop since CopyToPoints node already do iteration. It's just about thinking. Instead to bool with each box, you can first create whole geometry for bool difference (stamping cubes all around) and then you use single bool node to make subtraction against sphere.

Boolean.hip 

[Guest tar]

There is a swiss cheese example in the docs which does exactly what you are after, at the bottom of the page.

http://www.sidefx.com/docs/houdini/model/looping