# Generating a surface from points

Hello my friends,
i hope anybody can help me. I`m trying to create a Surface from coplanar Points.
I have a large terrain model and would like to generate Grass (with Vray, fur tool) on some parts of the terrain.
So i made a Point grid with the same distances as the ASCII grid and with the image sampler tool i cut out the points that i didnt needed. Then i projectetd the points on my terrain. But now i stuck because i could not figure out how to properly build a surface on wich i can use the fur tool.

I hope i´m not posting in the wrong spot here, (its my first time) if so pls put me in the wrong topic.

Thank you!

gh definition.gh (202.7 KB)

there are a couple of things: your terrain geometry is not internalized, and the output of the image sampler is also connected to the List input of the Cull Pattern

apart from that, why not just duplicating your Terrain mesh, cut it in parts and just keep the portions you want to generate random grass over, instead of creating a brand new geometry that -at the end- will have a conformation which is very similar to that very same portion of that mesh?

Use patch → convex hull of original points to split surface → quad remesh for a cleaner surface

Hi inno,

there you go, now i internalised the geometry, and i disconected the image sample from the cull pattern (it wasnt needed)

yeah cutting the surface would work too, if its possible with the image sampler tool. Because i like the workflow to whiten the spots of a orthophoto with photoshop.

Thanks in forward

gh definition.gh (12.6 MB)

I tried your approach but didnt understand it properly. I just get errors.

Can you help me out? I would be really gratefull!
gh definition.gh (12.6 MB)

Just put your points into convex hull then project the curve it outputs onto your surface, then split the surface using the projected curve. Bake and use quad remesh if you would like a cleaner surface.

Yes, i tried that. But convex hull doesnt recognise, that i have multiple seperated spots. It combines them to one large area.

you can use Point Groups to separate the areas like this:

then I would apply something like -maybe?- described in this discussion to generate good contours?

I didn’t go farther than this because your 12 megabyte mesh just melts my PC

1 Like