/// <summary>
/// Generar OBB a partir de AABB
/// </summary>
/// <param name="aabb">BoundingBox</param>
/// <returns>OBB generado</returns>
public static TgcObb.OBBStruct computeFromAABB(TgcBoundingBox.AABBStruct aabb)
{
OBBStruct obb = new OBBStruct();
obb.extents = (aabb.max - aabb.min) * 0.5f;
obb.center = aabb.min + obb.extents;
obb.orientation = new Vector3[] { new Vector3(1, 0, 0), new Vector3(0, 1, 0), new Vector3(0, 0, 1) };
return(obb);
}
/// <summary>
/// Indica si un BoundingSphere colisiona con un BoundingBox.
/// </summary>
/// <param name="sphere">BoundingSphere</param>
/// <param name="aabb">BoundingBox</param>
/// <returns>True si hay colisión</returns>
public static bool testSphereOBB(TgcBoundingSphere.SphereStruct sphere, TgcObb.OBBStruct obb)
{
//Transformar esfera a OBB-Space
TgcBoundingSphere.SphereStruct sphere2 = new TgcBoundingSphere.SphereStruct();
sphere2.center = obb.toObbSpace(sphere.center);
sphere2.radius = sphere.radius;
//Crear AABB que representa al OBB
Vector3 min = -obb.extents;
Vector3 max = obb.extents;
TgcBoundingBox.AABBStruct aabb = new TgcBoundingBox.AABBStruct();
aabb.min = min;
aabb.max = max;
return TgcCollisionUtils.testSphereAABB(sphere2, aabb);
}
/// <summary>
/// Interseccion Ray-OBB.
/// Devuelve true y el punto q de colision si hay interseccion.
/// </summary>
public static bool intersectRayObb(TgcRay ray, TgcObb obb, out Vector3 q)
{
//Transformar Ray a OBB-space
Vector3 a = ray.Origin;
Vector3 b = ray.Origin + ray.Direction;
a = obb.toObbSpace(a);
b = obb.toObbSpace(b);
TgcRay.RayStruct ray2 = new TgcRay.RayStruct();
ray2.origin = a;
ray2.direction = Vector3.Normalize(b - a);
//Crear AABB que representa al OBB
Vector3 min = -obb.Extents;
Vector3 max = obb.Extents;
TgcBoundingBox.AABBStruct aabb = new TgcBoundingBox.AABBStruct();
aabb.min = min;
aabb.max = max;
//Hacer interseccion Ray-AABB
if (TgcCollisionUtils.intersectRayAABB(ray2, aabb, out q))
{
//Pasar q a World-Space
q = obb.toWorldSpace(q);
return true;
}
return false;
}
