private Mesh GenerateAsteroidMesh(int asteroidCount)
{
var indices = new int[asteroidCount * 6];
var positions = new Vector3[asteroidCount * 4];
var normals = new Vector3[asteroidCount * 4];
var colours = new Color[asteroidCount * 4];
var uv0s = new Vector2[asteroidCount * 4];
var uv1s = new Vector2[asteroidCount * 4];
var size = (ringRadius + ringWidth + asteroidRadiusMax) * 2.0f;
var bounds = new Bounds(Vector3.zero, new Vector3(size, asteroidRadiusMax * 2.0f, size));
var uvStep = new Vector2(1.0f / (float)asteroidTextureTilesX, 1.0f / (float)asteroidTextureTilesY);
var ringRadiusInner = RingRadiusInner;
var ringRadiusOuter = RingRadiusOuter;
for (var i = 0; i < asteroidCount; i++)
{
// Index data
var indicesIndex = i * 6;
var vertexIndex = i * 4;
indices[indicesIndex + 0] = vertexIndex + 0;
indices[indicesIndex + 1] = vertexIndex + 1;
indices[indicesIndex + 2] = vertexIndex + 2;
indices[indicesIndex + 3] = vertexIndex + 3;
indices[indicesIndex + 4] = vertexIndex + 2;
indices[indicesIndex + 5] = vertexIndex + 1;
// Calculate asteroid values
var radius = Random.Range(asteroidRadiusMin, asteroidRadiusMax);
var radius2 = radius / SGT_Helper.InscribedBox;
var textureCellX = (float)Random.Range(0, asteroidTextureTilesX);
var textureCellY = (float)Random.Range(0, asteroidTextureTilesY);
var uvMin = new Vector2(uvStep.x * textureCellX, uvStep.y * textureCellY);
var uvMax = uvStep + uvMin;
var roll = Random.Range(-Mathf.PI, Mathf.PI);
var right = SGT_Helper.Rotate(Vector2.right * SGT_Helper.InscribedBox, roll);
var up = SGT_Helper.Rotate(Vector2.up * SGT_Helper.InscribedBox, roll);
var angle = Random.Range(-Mathf.PI, Mathf.PI);
var distance01 = GenerateDistance01();
var distance = SGT_Helper.Remap(0.0f, 1.0f, distance01, ringRadiusInner, ringRadiusOuter);
var rps = SGT_Helper.Clamp(Mathf.Lerp(orbitRateInner, orbitRateOuter, distance01) + Random.Range(-orbitRateDeviation, orbitRateDeviation), orbitRateInner, orbitRateOuter);
var height = Random.value;
var spinRate = Random.value;
var position = new Vector3(angle, distance, rps);
var colour = new Color(height, spinRate, 0.0f);
var uv1 = new Vector2(radius, radius2);
// Write star values into vertex data
positions[vertexIndex + 0] = position;
positions[vertexIndex + 1] = position;
positions[vertexIndex + 2] = position;
positions[vertexIndex + 3] = position;
colours[vertexIndex + 0] = colour;
colours[vertexIndex + 1] = colour;
colours[vertexIndex + 2] = colour;
colours[vertexIndex + 3] = colour;
normals[vertexIndex + 0] = SGT_Helper.NewVector3(-right + up, 0.0f);
normals[vertexIndex + 1] = SGT_Helper.NewVector3(right + up, 0.0f);
normals[vertexIndex + 2] = SGT_Helper.NewVector3(-right - up, 0.0f);
normals[vertexIndex + 3] = SGT_Helper.NewVector3(right - up, 0.0f);
uv0s[vertexIndex + 0] = new Vector2(uvMin.x, uvMax.y);
uv0s[vertexIndex + 1] = new Vector2(uvMax.x, uvMax.y);
uv0s[vertexIndex + 2] = new Vector2(uvMin.x, uvMin.y);
uv0s[vertexIndex + 3] = new Vector2(uvMax.x, uvMin.y);
uv1s[vertexIndex + 0] = uv1;
uv1s[vertexIndex + 1] = uv1;
uv1s[vertexIndex + 2] = uv1;
uv1s[vertexIndex + 3] = uv1;
}
var asteroidMesh = new Mesh();
asteroidMesh.hideFlags = HideFlags.DontSave;
asteroidMesh.vertices = positions;
asteroidMesh.triangles = indices;
asteroidMesh.normals = normals;
asteroidMesh.colors = colours;
asteroidMesh.uv = uv0s;
asteroidMesh.uv1 = uv1s;
asteroidMesh.bounds = bounds;
return(asteroidMesh);
}