/// <summary>
/// Generates a convex hull collision mesh from the given original mesh.
/// </summary>
/// <param name="original"></param>
/// <returns></returns>
public static Mesh GenerateCollisionMesh(Mesh original, Vector3 offset = default(Vector3), float margin = 0f)
{
if (margin > 0f)
{
ConvexHullShape tempShape = new ConvexHullShape(Array.ConvertAll(original.vertices, x => x.ToBullet()), original.vertices.Length);
tempShape.Margin = 0f;
ShapeHull shapeHull = new ShapeHull(tempShape);
bool b = shapeHull.BuildHull(0f);
AlignedVector3Array initialVertices = new AlignedVector3Array();
for (int i = 0; i < shapeHull.NumVertices; i++)
{
initialVertices.Add(shapeHull.Vertices[i]);
}
List <BulletSharp.Math.Vector4> planeEquations = GeometryUtilEx.GetPlaneEquationsFromVertices(initialVertices);
List <BulletSharp.Math.Vector4> shiftedPlaneEquations = new List <BulletSharp.Math.Vector4>();
for (int i = 0; i < planeEquations.Count; i++)
{
BulletSharp.Math.Vector4 plane = planeEquations[i];
plane.W += margin;
shiftedPlaneEquations.Add(plane);
}
List <BulletSharp.Math.Vector3> shiftedVertices = GeometryUtilEx.GetVerticesFromPlaneEquations(shiftedPlaneEquations);
Vector3[] finalVertices = new Vector3[shiftedVertices.Count];
Mesh collisionMesh = new Mesh();
for (int i = 0; i < finalVertices.Length; i++)
{
finalVertices[i] = shiftedVertices[i].ToUnity() - offset;
}
collisionMesh.vertices = finalVertices;
collisionMesh.RecalculateBounds();
return(collisionMesh);
}
else
{
ConvexHullShape tempShape = new ConvexHullShape(Array.ConvertAll(original.vertices, x => x.ToBullet()), original.vertices.Length);
tempShape.Margin = 0f;
ShapeHull shapeHull = new ShapeHull(tempShape);
bool b = shapeHull.BuildHull(0f);
Mesh collisionMesh = new Mesh();
Vector3[] vertices = new Vector3[shapeHull.NumVertices];
for (int i = 0; i < vertices.Length; i++)
{
vertices[i] = shapeHull.Vertices[i].ToUnity() - offset;
}
int[] triangles = new int[shapeHull.NumIndices];
for (int i = 0; i < triangles.Length; i++)
{
triangles[i] = (int)shapeHull.Indices[i];
}
collisionMesh.vertices = vertices;
collisionMesh.triangles = triangles;
collisionMesh.RecalculateNormals();
collisionMesh.RecalculateBounds();
return(collisionMesh);
}
}
public static unsafe System.Numerics.Vector4 ToNumerics(this BulletSharp.Math.Vector4 v) => *(System.Numerics.Vector4 *) & v;
