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### #ActualBuckslice

Posted 18 March 2014 - 05:17 PM

Hello gamedev.net,

I'm programming a 3D space game in Unity using c# and I've run into a bit of a problem with my planet generation. I have code right now that generates on icosphere and applies simplex noise to it, it looks pretty good but I'm getting weird noise striations along the side of the planet. It looks like the noise is getting stretched along parts of the planet.

Here's the relevant code. it just loops through each vertex i in vertices[] which are all unit length along a subdivided icosphere and applies some noise to it. They end up ranging from about 0.85f - 1.15f afterwards and then I just scale it up for however big I want the planet to be.

float random = Random.Range(100f, 1000f);

for(int i = 0; i < vertices.length; i++){
float noiseDensity = 2f;
Vector3 v = vertices[i];
v.Scale(new Vector3(noiseDensity, noiseDensity, noiseDensity));
float scale = .25f;
float noise1 = Noise.Noise.GetOctaveNoise(v.x + random, v.y + random, v.z + random, 4) * scale;
float factor = 1f - (scale / 2f) + noise1;
vertices[i] = Vector3.Scale(vertices[i], new Vector3(factor, factor, factor));
}


I tried sampling the noise in multiple spots and average them together to try to smooth it out but I couldn't get it looking good really. I'm quite new to noise and such but I thought if I used 3D noise it wouldn't matter what shape I applied it to, but perhaps the icosphere is the problem because you can't really map a grid to it without distortions. I really don't want to use a normal sphere though because their triangles aren't as consistent of a size. If you guys have any ideas on how I could fix this problem that would be great! I wasn't sure if this was the right forum to post on but it seemed more about the math of applying noise than about rendering or graphics. Thanks!

Here's a few pictures of how it looks:

looks good here

[attachment=20446:Unity 2014-03-16 15-44-06-31.png]

turn the planet a little and you can see the weird stretching I'm talking about

[attachment=20445:Unity 2014-03-16 15-45-29-03.png]

on the left it looks good but then to the right you can see the stretching

[attachment=20444:Unity 2014-03-16 15-48-28-65.png]

### #1Buckslice

Posted 16 March 2014 - 05:02 PM

Hello gamedev.net,

I'm programming a 3D space game in Unity using c# and I've run into a bit of a problem with my planet generation. I have code right now that generates on icosphere and applies simplex noise to it, it looks pretty good but I'm getting weird noise striations along the side of the planet. It looks like the noise is getting stretched along parts of the planet.

Here's the relevant code. it just loops through each vertex i in vertices[] which are all unit length along a subdivided icosphere and applies some noise to it. They end up ranging from about 0.85f - 1.15f afterwards and then I just scale it up for however big I want the planet to be.

float random = Random.Range(100f, 1000f);

for(int i = 0; i < vertices.length; i++){
float noiseDensity = 2f;
Vector3 v = vertices[i];
v.Scale(new Vector3(noiseDensity, noiseDensity, noiseDensity));
float scale = .25f;
float noise1 = Noise.Noise.GetOctaveNoise(v.x + random, v.y + random, v.z + random, 4) * scale;
float factor = 1f - (scale / 2f) + noise1;
vertices[i] = Vector3.Scale(vertices[i], new Vector3(factor, factor, factor));
}


I tried sampling the noise in multiple spots and average them together to try to smooth it out but I couldn't get it looking good really. I'm quite new to noise and such but I thought if I used 3D noise it wouldn't matter what shape I applied it to, but perhaps the icosphere is the problem because you can't really map a grid to it without distortions. I really don't want to use a normal sphere though because their triangles aren't as consistent of a size. If you guys have any ideas on how I could fix this problem that would be great! I wasn't sure if this was the right forum to post on but it seemed more about the math of applying noise than about rendering or graphics. Thanks!

Here's a few pictures of how it looks:

looks good here

[attachment=20446:Unity 2014-03-16 15-44-06-31.png]

turn the planet a little and you can see the weird stretching I'm talking about

[attachment=20445:Unity 2014-03-16 15-45-29-03.png]

on the left it looks good but then to the right you can see the stretching

[attachment=20444:Unity 2014-03-16 15-48-28-65.png]

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