How do I guarantee a generated sphere's mesh is facing outward?

Question

I have an algorithm that generates a sphere (which will eventually become a planet generator).

According to this post, http://answers.unity3d.com/questions/231141/why-does-my-script-made-mesh-only-look-visible-fro.html the answer says "The order which the vertices are linked determines which direction they face."

How do I order the vertices to guarantee they are facing outward?

Answer 1

Best Answer

Answer by giulio-pierucci · Feb 10, 2015 at 08:57 PM

You'd organize vertices (index or triagles) clockwise:

and use Mesh.RecalculateNormals.

Otherwise, you can write normal vectors in mesh with (vertexPos - center).normalized

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Elenesski · Feb 10, 2015 at 09:36 PM 0

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I'll have to go back and try to figure out what "clockwise" means in terms of the vertex positions the algorithm calculates.

giulio-pierucci · Feb 11, 2015 at 11:23 AM 0

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You can set normal manually.

BTW clockwise is represented by image on link.

TRIANGLE 1 indexes: 1 2 4 TRIANGLE 2 indexes: 2 3 4

Elenesski · Feb 11, 2015 at 08:15 PM 0

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$$anonymous$$y indicies are ordered ascending as in the example, but it doesn't resolve the problem.

giulio-pierucci · Feb 11, 2015 at 08:20 PM 0

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Set up normal manually. It had to work, i wrote a custom halo system with Dynamic $$anonymous$$esh

Elenesski · Feb 11, 2015 at 09:31 PM 1

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I fixed the problem by rewriting the way the algorithm generates the triangles.