/**
* Get a weighted value for the quality of a quad composed of two triangles. 0 is terrible, 1 is perfect.
* normalThreshold will discard any quads where the dot product of their normals is less than the threshold.
* @todo Abstract the quad detection to a separate class so it can be applied to pb_Objects.
*/
static float GetQuadScore(this ProBuilderMesh mesh, WingedEdge left, WingedEdge right, float normalThreshold = .9f)
{
Vertex[] vertices = mesh.GetVertices();
int[] quad = WingedEdge.MakeQuad(left, right);
if (quad == null)
{
return(0f);
}
// first check normals
Vector3 leftNormal = Math.Normal(vertices[quad[0]].position, vertices[quad[1]].position, vertices[quad[2]].position);
Vector3 rightNormal = Math.Normal(vertices[quad[2]].position, vertices[quad[3]].position, vertices[quad[0]].position);
float score = Vector3.Dot(leftNormal, rightNormal);
if (score < normalThreshold)
{
return(0f);
}
// next is right-angle-ness check
Vector3 a = (vertices[quad[1]].position - vertices[quad[0]].position);
Vector3 b = (vertices[quad[2]].position - vertices[quad[1]].position);
Vector3 c = (vertices[quad[3]].position - vertices[quad[2]].position);
Vector3 d = (vertices[quad[0]].position - vertices[quad[3]].position);
a.Normalize();
b.Normalize();
c.Normalize();
d.Normalize();
float da = Mathf.Abs(Vector3.Dot(a, b));
float db = Mathf.Abs(Vector3.Dot(b, c));
float dc = Mathf.Abs(Vector3.Dot(c, d));
float dd = Mathf.Abs(Vector3.Dot(d, a));
score += 1f - ((da + db + dc + dd) * .25f);
// and how close to parallel the opposite sides area
score += Mathf.Abs(Vector3.Dot(a, c)) * .5f;
score += Mathf.Abs(Vector3.Dot(b, d)) * .5f;
// the three tests each contribute 1
return(score * .33f);
}