Winding issues when creating boolean slicer?

[sdlovecraft]

Hey forum!

I'm attempting to create a boolean/slicer function, where I can slice up the geometry of an object (https://www.sidefx.com/tutorials/building-the-slicer-setup-in-houdini/ this sort of thing).

However it seems that I'm having an issue with the way that the primitives are being 'winded' by the boolean operator.  When I try and polyextrude the slices created by the 'boolean' they go up and down randomly rather than just 'up'.

It seems that no vertex/point/primitive attribute is affecting the polyextrudes understanding of 'UP'  - i've read its calculated from some kind of ordering of vertex?

Anyone have any ideas about how to fix this?

I have attached a very minimal houdini file and an image of the problem.

Thanks!

<3

Sam

winding_polyextrude.hip

Edited June 18, 2018 by sdlovecraft

[nikosgr00]

Hi Sam,

Polyextrude makes the extrusion, based on normals. Add the direction you want using a Point Sop, and inside Poly extrude choos Point Normal/Existing.

 

sorry for my english.

winding_polyextrude_01.hipnc

Edited June 18, 2018 by nikosgr00

[Noobini]

you seem to complicate things quite a bit...

01) the boolean should treat the cutting surfaces as.............SURFACES.....not solid

02) the boolean operation should simply be intersect...no need for any seams

so if you keep it simple and logical as that...it 'just works'

winding_polyextrude_simple.hipnc

[sdlovecraft]

Ah great, problem fixed. Thanks a lot