public bool Intersects(CollisionContent cc, ref AABB box)
{
// transform to box-relative coordinates
// triangle culled by box major axes?
Vector3 bc = box.Center;
Vector3 va = cc.Vertices[VertexA] - bc;
Vector3 vb = cc.Vertices[VertexB] - bc;
Vector3 vc = cc.Vertices[VertexC] - bc;
return(AABBIntersects(ref va, ref vb, ref vc, ref box));
}
internal bool Intersects(CollisionContent cc, ref OBB box)
{
Vector3 bc = box.Pos;
Vector3 va = cc.Vertices[VertexA] - bc;
Vector3 vb = cc.Vertices[VertexB] - bc;
Vector3 vc = cc.Vertices[VertexC] - bc;
Vector3.TransformNormal(ref va, ref box.InvOriMatrix, out va);
Vector3.TransformNormal(ref vb, ref box.InvOriMatrix, out vb);
Vector3.TransformNormal(ref vc, ref box.InvOriMatrix, out vc);
tempAABB.Set(-box.HalfDim, box.HalfDim);
return(AABBIntersects(ref va, ref vb, ref vc, ref tempAABB));
}
public void CalcColl(CollisionContent cc)
{
U = cc.Vertices[VertexB] - cc.Vertices[VertexA];
V = cc.Vertices[VertexC] - cc.Vertices[VertexA];
uu = U.LengthSquared();
vv = V.LengthSquared();
uv = Vector3.Dot(U, V);
float d = uv * uv - uu * vv;
if (Math.Abs(d) < 1e-10f)
{
throw new InvalidOperationException(String.Format(
"Degenerate triangle {1} in mesh. Verts: {2} {3} {4}", this,
cc.Vertices[VertexA], cc.Vertices[VertexB], cc.Vertices[VertexC]));
}
di = 1.0f / d;
}
public bool Intersects(CollisionContent cc, ref Ray collRay, ref float dd)
{
Vector3 P = cc.Vertices[VertexA];
Vector3 w0 = collRay.Position - P; // ray position in triangle space
float b = Vector3.Dot(Normal, collRay.Direction);
if (-b < 1e-10) // ray is in plane, or pointing at backside of tri
{
return(false);
}
float a = Vector3.Dot(Normal, w0);
if (a < 0)
{
return(false); // ray starts below triangle
}
float r = -a / b;
if (r > dd)
{
return(false); // triangle too far away
}
Vector3 I = collRay.Position + collRay.Direction * r;
Vector3 W = I - P;
float uw = Vector3.Dot(U, W);
float vw = Vector3.Dot(V, W);
float s = (uv * vw - vv * uw) * di;
if (s < CollMin || s > CollMax) // outside in "s" space
{
return(false);
}
float t = (uv * uw - uu * vw) * di;
if (t < CollMin || (s + t) > CollMax) // outside in "s-t" space
{
return(false);
}
// found an intersection
dd = r;
return(true);
}
public bool Intersects(ref Triangle t, CollisionContent cc)
{
return(t.Intersects(cc, ref sphere));
}
internal bool Intersects(CollisionContent cc, ref BoundingSphere sphere)
{
// Test triangle plane against sphere
float sd;
Vector3.Dot(ref sphere.Center, ref Normal, out sd);
if (sd < Distance - sphere.Radius || sd > Distance + sphere.Radius)
{
return(false);
}
Vector3 pc;
Vector3.Multiply(ref Normal, Distance - sd, out pc);
Vector3.Add(ref pc, ref sphere.Center, out pc);
// Find the closest point on each edge of the triangle
// Set up the triangle vertices
Vector3 a = cc.Vertices[this.VertexA];
Vector3 b = cc.Vertices[this.VertexB];
Vector3 c = cc.Vertices[this.VertexC];
// Calculate the edges (non-normalized)
Vector3 ba, cb, ac;
Vector3.Subtract(ref b, ref a, out ba);
Vector3.Subtract(ref c, ref b, out cb);
Vector3.Subtract(ref a, ref c, out ac);
// Find the square of the length of the edges
float lba, lcb, lac;
Vector3.Dot(ref ba, ref ba, out lba);
Vector3.Dot(ref cb, ref cb, out lcb);
Vector3.Dot(ref ac, ref ac, out lac);
// Calculate vertex-relative position of sphere center
Vector3 pca, pcb, pcc;
Vector3.Subtract(ref pc, ref a, out pca);
Vector3.Subtract(ref pc, ref b, out pcb);
Vector3.Subtract(ref pc, ref c, out pcc);
// Caluclate length-scaled distance along each edge
float dab, dbc, dca;
Vector3.Dot(ref ba, ref pca, out dab);
Vector3.Dot(ref cb, ref pcb, out dbc);
Vector3.Dot(ref ac, ref pcc, out dca);
// calculate 0..1 barycentric coordinate for each edge
float vba = dab / lba;
float vcb = dbc / lcb;
float vac = dca / lac;
// Test barycentric coordinates: if (s >= 0) and (t >= 0) and (s + t <= 1) we're inside.
// Because I've wound each edge, I have to negate one of them (and I only need 2)
if (vba >= 0 && (1 - vac) >= 0 && vba + (1 - vac) <= 1)
{
return(true);
}
float r2 = sphere.Radius * sphere.Radius;
float d;
// find actual points, clipped to triangle, and test distance to sphere center
// B-A
if (vba < 0)
{
ba = a;
}
else if (vba > 1)
{
ba = b;
}
else
{
Vector3.Multiply(ref ba, vba, out ba);
Vector3.Add(ref ba, ref a, out pca);
}
Vector3.Subtract(ref pca, ref sphere.Center, out pca);
Vector3.Dot(ref pca, ref pca, out d);
if (d <= r2)
{
return(true);
}
// C-B
if (vcb < 0)
{
cb = b;
}
else if (vcb > 1)
{
cb = c;
}
else
{
Vector3.Multiply(ref cb, vcb, out cb);
Vector3.Add(ref cb, ref b, out pcb);
}
Vector3.Subtract(ref pcb, ref sphere.Center, out pcb);
Vector3.Dot(ref pcb, ref pcb, out d);
if (d <= r2)
{
return(true);
}
// A-C
if (vac < 0)
{
ac = c;
}
else if (vac > 1)
{
ac = a;
}
else
{
Vector3.Multiply(ref ac, vac, out ac);
Vector3.Add(ref ac, ref c, out pcc);
}
Vector3.Subtract(ref pcc, ref sphere.Center, out pcc);
Vector3.Dot(ref pcc, ref pcc, out d);
if (d <= r2)
{
return(true);
}
// nothing fit
return(false);
}
public bool Intersects(ref Triangle t, CollisionContent cc)
{
float dd = collRayD;
return(t.Intersects(cc, ref collRay, ref dd));
}
