## Scattering around pre-existing geometry

General Discussion about Isotropix and CG related topics

### Scattering around pre-existing geometry

Okay another quick question, and I feel like this should be fairly straight forward but I cannot for the life of me find the answer.

I just want to scatter points AROUND existing geometry. So, I have some buildings in a forest, and I don't want the tree to scatter where the buildings are! Or I have some rocks, and I don't want the tree to scatter overtop the rocks. Keep in mind, the buildings and/or rocks are manually placed and not scattered!

kai_wheatley

Posts: 19
Joined: Fri Apr 26, 2019 11:00 pm

### Re: Scattering around pre-existing geometry

There are a couple of ways to do it, scopes is one, but perhaps the easier way is to add collision objects in the scatterer, the column to the right of probability, though obviously being able to use scopes properly is high on the list of things to get your head around, can't say I understand fully what can be done with them but i'll keep watching the video's and eventually it will sink in
I think it would be really cool if one scatterer knew where the objects of another scatterer where so as to avoid placing objects there, but I suppose thats asking too much of the system, and where better project management/planning comes into it, and figuring out your own way to implement things you have learned, there are many video's I've watched where I cant figure out how I would use certain things.
RayCaster

Posts: 18
Joined: Fri Oct 11, 2019 5:02 pm

### Re: Scattering around pre-existing geometry

Yeah I was looking into scopes but don't quite understand how to use them yet.. Adding the collision objects doesn't work because you can only add one object(at least I think you can only add one). That, as far as I can tell, is basically just using a single geometry as a bounding box for the scatterer, whereas I have many manually placed geometries that I wan't all the scattered objects to avoid.
kai_wheatley

Posts: 19
Joined: Fri Apr 26, 2019 11:00 pm

### Re: Scattering around pre-existing geometry

You can add one per scattered item, though I dont know if that just changes the shape of the bounding box for that item, or if they avoid that item, if its avoid then the object would be placed where you didnt want items, but perhaps it doesnt work that way. Though once you have a working scope setup you have it for anything that needs it and from there it shouldnt be too hard to get it working as you want. Perhaps do a search for pre-made scope example to build on.
RayCaster

Posts: 18
Joined: Fri Oct 11, 2019 5:02 pm

### Re: Scattering around pre-existing geometry

Hi,

You have to decimate points with an occlusion texture. Here is an example. I decimate the points that are used to scatter the boxes with the occlusion made by the spheres.

Decimate_with_Occlusion.project

Also have a look at that: https://www.isotropix.com/learn/tutoria ... -occlusion

Cheers
Démian
Isotropix
Technical Artist - Clarisse Specialist

dboude

Posts: 1415
Joined: Mon Jul 03, 2017 10:51 am

### Re: Scattering around pre-existing geometry

Thanks! The occlusion set up works.
kai_wheatley

Posts: 19
Joined: Fri Apr 26, 2019 11:00 pm