P-152: Virtual World Concept Update 20: Spherical Terrain: 3D Perlin Noise

I believe I have fixed the seaming problem and generated a sphere displaced with seamless noise.

I was looking at this problem the wrong way. I was looking at the sphere as a combination of six flat planes, and trying to apply 2D noise to each plane, similiar to the way a standard terrain would be created. This created seams between the six sides of the quad sphere.

However, even though the sphere is create from a projected cube, this is not the correct way to apply noise to it. I should have looked at it as a regular sphere, and used a 3D noise function to take in the x,y, and z coordinates of the sphere as inputs. This is what I have now done.

I am using libnoise, and opensource noise library. After generating the noise value using the coordinates of the sphere as inputs, I am then displacing each point on the sphere along it’s normal. This is the critical step that I was missing for a while. In order for the sphere points to displace in the correct direction, the normal needs to be taken into account.

The sphere looks more like an asteroid now, rather than a planet, but fixing that can be done by configuring the noise function.

The next step is to work on procedural texturing of the sphere. I intend to use the height value of the individual points to paint different textures, mountains would be while, low areas blue, areas in the middle green, etc etc.