Creating planet-like sphere from heightmaps

It’s my first post on the forum so I want to say hello to all.

Moving onto my problem, I want to create a planet object using 6 heightmaps arranged in the cube-like structure and mapped to sphere as described in the article Mapping a Cube to a Sphere.
What I would like to know is whether I will have to reimplement some parts of Terrain class or is it possible to do this manipulating some of its data / using other existing features. I haven’t seen a definitive answer to the question on the forum. I don’t want to waste too much time looking into a solution that might be a dead end so if there is a different, simpler way to reach the same effect, please let me know.

Have you seen @vivienneanthony’s work?

Also, welcome to the forums! :confetti_ball:

Thanks for the answer :).
Yes, I have seen @vivienneanthony’s work, but from what I understand, he has rewritten Terrain class to support cube to sphere mapping (mind you - I’m new to Urho3D and might be wrong). Optimmally, I would like to do this without having to understand the inner workings of the library - 3D simulation is just a part of my project. I have raised the question because in the reported issue Creating a quad cube planet! @Lumak has written something about the method.

That’s not possible without modifying the terrain class.

It only supports a single-axis of displacement so even using the RG 16-bit encoding you won’t get a spherical result out of it. Most of its’ support functions (normals and the like) are also written with the assumption of a heightmap so all of those are now meaningless.

Vertex-shader fudgery to push out the vertices along the face tangent is fudgery and will not work even just for rendering as your patch bounding boxes will be incorrect- nevermind the other issues when you have to deal with collision.

Even if you fudge things to make it work … you’ll already be in there making changes to make the fudgery work so you might as well as deal with it appropriately from the get-go. It’s a specialized task.

I didn’t write anything with the cube-to-sphere conversion, just merely linked what I thought was more direct method using a mathematical conversion compared to the other programmatic approach. The following cubed terrain picture was just rotation of the nodes for each terrain to shape it into a cube. And I didn’t keep any of that code.

Yeah, I feared that would be the answer :frowning: . Well, I will probably start with trying to understand @vivienneanthony’s work. Nevertheless, thanks again for quick response.

You can check out the document pdf in Dropbox - Procedurus_Source.zip - Simplify your life. Right now I’m working with during it using no shader then shaders.

As mentioned, its my work in progress. In some ways a working version would be awesome. Maybe a little game changing. Although some of the code might look similiar to Urho3D Terrain and TerrainPatch. This is a different beast technically. The physics part I think would work the same but the visual part would be different. Since, a working version can possibly lead to planet size Terrain. I think it changes a lot in how Urho3D would handle showing distance. I can better describe it but check out the pdf because it explains a lot.