public void CheckTriangleBoundingBox(Triangle tri, List <Vector3> vertexes, List <Vector3> normals)
{
List <Vector3> triVerts = new List <Vector3>();
for (int i = 0; i < 3; i++)
{
Vector3 origVert = vertexes[tri.VertexIndices[i]];
triVerts.Add(new Vector3(origVert.X - 100, origVert.Y - 100, origVert.Z - 100));
}
BoundingBox triBounds = new BoundingBox(triVerts);
Vector3 triCenter = (triBounds.Maximum + triBounds.Minimum) / 2;
Vector3 triHalfWidth = (triBounds.Maximum - triBounds.Minimum) / 2;
Vector3 boxCenter = (Bounds.Maximum + Bounds.Minimum) / 2;
Vector3 boxHalfWidth = (Bounds.Maximum - Bounds.Minimum) / 2;
if (Math.Abs(triCenter.X - boxCenter.X) > (triHalfWidth.X + boxHalfWidth.X))
{
return;
}
if (Math.Abs(triCenter.Y - boxCenter.Y) > (triHalfWidth.Y + boxHalfWidth.Y))
{
return;
}
if (Math.Abs(triCenter.Z - boxCenter.Z) > (triHalfWidth.Z + boxHalfWidth.Z))
{
return;
}
// If we got here, there is an intersection
AllIntersectingTris.Add(tri);
if (IsFloor(normals[tri.NormalIndex]))
{
FloorIntersectingTris.Add(tri);
}
}
// Code copied from https://stackoverflow.com/questions/17458562/efficient-aabb-triangle-intersection-in-c-sharp
public void CheckTriangle(Triangle tri, List <Vector3> vertexes, List <Vector3> normals)
{
List <Vector3> triVerts = new List <Vector3>();
triVerts.Add(vertexes[tri.VertexIndices[0]]);
triVerts.Add(vertexes[tri.VertexIndices[1]]);
triVerts.Add(vertexes[tri.VertexIndices[2]]);
Vector3 normal = normals[tri.NormalIndex];
// This will test the nox normals' axes
float triangleMin, triangleMax;
Vector3[] boxNormals = new Vector3[]
{
new Vector3(1, 0, 0),
new Vector3(0, 1, 0),
new Vector3(0, 0, 1)
};
for (int i = 0; i < 3; i++)
{
Vector3 n = boxNormals[i];
Project(triVerts, boxNormals[i], out triangleMin, out triangleMax);
if (triangleMax < Bounds.Minimum[i] || triangleMin > Bounds.Maximum[i])
{
return;
}
}
List <Vector3> boxVertices = new List <Vector3>();
boxVertices.Add(Bounds.Minimum);
boxVertices.Add(new Vector3(Bounds.Maximum.X, Bounds.Minimum.Y, Bounds.Minimum.Z));
boxVertices.Add(new Vector3(Bounds.Minimum.X, Bounds.Maximum.Y, Bounds.Minimum.Z));
boxVertices.Add(new Vector3(Bounds.Minimum.X, Bounds.Minimum.Y, Bounds.Maximum.Z));
boxVertices.Add(new Vector3(Bounds.Maximum.X, Bounds.Maximum.Y, Bounds.Minimum.Z));
boxVertices.Add(new Vector3(Bounds.Maximum.X, Bounds.Minimum.Y, Bounds.Maximum.Z));
boxVertices.Add(new Vector3(Bounds.Minimum.X, Bounds.Maximum.Y, Bounds.Maximum.Z));
boxVertices.Add(Bounds.Maximum);
float boxMin, boxMax;
float triangleOffset = Vector3.Dot(normal, triVerts[0]);
Project(boxVertices, normal, out boxMin, out boxMax);
if (boxMax < triangleOffset || boxMin > triangleOffset)
{
return;
}
List <Vector3> triangleEdges = new List <Vector3>();
triangleEdges.Add(vertexes[tri.VertexIndices[0]] - vertexes[tri.VertexIndices[1]]);
triangleEdges.Add(vertexes[tri.VertexIndices[1]] - vertexes[tri.VertexIndices[2]]);
triangleEdges.Add(vertexes[tri.VertexIndices[2]] - vertexes[tri.VertexIndices[0]]);
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
Vector3 axis = Vector3.Cross(triangleEdges[i], boxNormals[j]);
Project(boxVertices, axis, out boxMin, out boxMax);
Project(triVerts, axis, out triangleMin, out triangleMax);
if (boxMax < triangleMin || boxMin > triangleMax)
{
return;
}
}
}
// If we got this far, that means there's an intersection! Hooray!
AllIntersectingTris.Add(tri);
if (IsFloor(normal))
{
FloorIntersectingTris.Add(tri);
}
}
