The Seventh World

What's the idea with bringing in the bottom four points?

I'm hoping it creates more of a floating island look rather than a cube with mountains.  Something like this but less of a point at the bottom.

I didn't realise I could use 3D noise to create a heightmap without creating caves. 

This is using a sphere as the base and then sampling 3D simplex noise to create the terrain on that sphere.  What I did in Leadwerks was project a heightmap onto the face of a cube to render the terrain and I was going to do the same thing in Ultra too but the whole process of blending all the maps together is very convoluted.  This is actually very simple.

float CalculateTerrainSurface(shared_ptr<VoxelObject> voxel_object, shared_ptr<VoxelBrush> brush, VoxelNode* node, Decimal3& position) {
    float radius = 32.0f;
    float size = voxel_object->GetSize();
    auto centre = voxel_object->GetPosition();
    Decimal3 local_pos = {position.x - centre.x, position.y - centre.y, position.z - centre.z};

    auto dist = sqrt((local_pos.x * local_pos.x) + (local_pos.y * local_pos.y) + (local_pos.z * local_pos.z)) - radius;
    return dist + noise->GetFractal(4, position.x / size, position.y / size, position.z / size) * 16.0f;
}

I think I can apply this to the cuboid shape I made above and then further manipulate how the terrain is made before eroding it.  I'm not sure yet, but I think I'll have to project the height values onto some 2D planes so I can perform erosion on them and then map them back.  Otherwise I'll have to erode either a cube map of points or the voxel octree itself.  The former will take a lot of memory for large terrains and the latter will probably far too slow.

Food for thought!

A cube is the base shape here.  I think it will work a lot better if I make a bevelled cube or simply squash the sphere a little for each face.  But the edges are practically seamless without any extra processing.

An SDF cube with a corner radius was the way to go.  It's so annoying how you can spend months getting something to work then realise there is a 5 minute method that is so much better.

10 hours ago, SpiderPig said:

It's so annoying how you can spend months getting something to work then realise there is a 5 minute method that is so much better.

This happens to me when I am working too much / too hard. Some of my biggest wastes of time were when I was in crunch mode and I went in a wrong direction.

You might also want to check out the cubesphere shape:
https://www.ultraengine.com/learn/CreateCubeSphere?lang=cpp

Yeah I think if you spend too long trying to solve a problem then it's probably not worth it.  At least maybe until all other options have been explored enough to form a decision on.

Got it pretty much looking the way I wanted.

float CalculateTerrainSurface(shared_ptr<VoxelObject> voxel_object, shared_ptr<VoxelBrush> brush, VoxelNode* node, Decimal3& position) {
    float radius = 32.0f;
    float size = voxel_object->GetSize();
    auto centre = voxel_object->GetPosition();

    auto ratio = 1.0f;
    auto local_y = position.y - centre.y + radius;
    if (local_y < radius * 2.0f) {
        ratio = 0.75f + (local_y / (radius * 2.0f)) / 3.0f;
    }

    auto dist = sdfBox(Vec3(centre.x, centre.y, centre.z), Vec3(radius * ratio, radius, radius * ratio), Vec3(position.x, position.y, position.z), 16.0f * ratio);
    return dist + (noise->GetFractal(8, position.x / size, position.y / size, position.z / size) + 1.0f) / 2.0f * 16.0f;
}

 

This is a 2k Voxel Terrain with tri-planer texturing.  It's just diffuse right now, and the red is an area that will be textured differently.   It's coming along nicely.  I think I'll work on normal maps and smooth shading.

The LOD algorithm needs work, the detail in the terrain falls off too sharply I feel.