Itoo Software Forum

Author Topic: Edge mode with secondary paint areas  (Read 1662 times)


  • Newbie
  • *
  • Posts: 10
Edge mode with secondary paint areas
« on: August 04, 2018, 04:15:54 AM »
I'm trying to use edge mode in vray.

On the base surface, object A is scattered and uses edge mode. Edge mode works.
On an additional paint layer, I'm scattering only object B using edge mode. Edge mode does NOT work - the entire object B is rendered for every instance. Nor does the paint layer use edge mode if I select object A only, nor even if there is only one geometry (if I delete object B completely).

Does edge mode only work with a single base surface layer and not on any additional paint layers?



  • Administrator
  • Hero Member
  • *****
  • Posts: 4044
    • iToo Software
Re: Edge mode with secondary paint areas
« Reply #1 on: August 04, 2018, 09:26:45 AM »
Hi Matt,

Yes, i can confirm this issue, which we had not noticed until now.

The problem is that each area uses internally its own spline to perform the edge clipping.
For surfaces, Forest extracts the edge of the geometry (in a process similar to Editable Poly->Border->Create Shape). For Paint, the area is converted internally to a spline.

But when a Paint area is used together a surface, Forest excludes the complete items which are outside of the surface... but the edge clipping is performed only with the Paint spline, not with the Surface spline.
To make it correctly, it should necessary to combine both the surface and paint splines, probably using a boolean intersection process.

I logged the issue in our to-do list, but i'm afraid it has not a simple solution. We'll see what can be done.

Meanwhile, i suggest you convert the Paint area to a spline (it can be done from the Area rollup). And then edit the spline, clipping it within the limits of the surface.
It can be done manually, or extracting the surface edge and combining both with the Editable Spline boolean tools.

Carlos Quintero
iToo Software


  • Newbie
  • *
  • Posts: 10
Re: Edge mode with secondary paint areas
« Reply #2 on: August 06, 2018, 07:14:12 PM »
Thanks for clarifying Carlos. Glad you saw the issue. However, when you wrote that:

... but the edge clipping is performed only with the Paint spline, not with the Surface spline.

I actually found it to be the opposite way: the edge clipping was performed on the base Surface spline, not the Paint spline.

Anyways, the work around I finally got was to make a copy of the Forest object, make the new Forest's surface level have the selected geometry, distribution, and density that I wanted previously for my paint layer, have this new surface's edge mode on, and then add a new paint layer as an EXCLUDE layer. This exclude paint layer has the regular point mode, not edge mode, and I basically painted away 95% of the surface, everything except the awkward corners that did not get filled by the first Forest object.

That worked. Probably not an efficient workflow if you have a lot of paint layers, but for this it was fine. I did not use the "paint-spline-export-then-boolean-shape-intersection" method because my base surface was not flat.