public void BuildDecal(Decal decal)
{
MeshFilter filter = decal.GetComponent <MeshFilter>();
if (filter == null)
{
filter = decal.gameObject.AddComponent <MeshFilter>();
}
if (decal.GetComponent <Renderer>() == null)
{
decal.gameObject.AddComponent <MeshRenderer>();
}
decal.Material = decal.GetComponent <Renderer>().material;
if (decal.Material == null || decal.Sprite == null)
{
filter.mesh = null;
return;
}
_affectedObjects = GetAffectedObjects(decal.GetBounds(), decal.AffectedLayers);
foreach (GameObject go in _affectedObjects)
{
DecalBuilder.BuildDecalForObject(decal, go);
}
DecalBuilder.Push(decal.PushDistance);
Mesh mesh = DecalBuilder.CreateMesh();
if (mesh != null)
{
mesh.name = "DecalMesh";
filter.mesh = mesh;
}
}
public static void BuildDecalForObject(Decal decal, GameObject affectedObject)
{
Mesh affectedMesh = affectedObject.GetComponent <MeshFilter>().sharedMesh;
if (affectedMesh == null)
{
return;
}
float maxAngle = decal.MaxAngle;
Plane right = new Plane(Vector3.right, Vector3.right / 2f);
Plane left = new Plane(-Vector3.right, -Vector3.right / 2f);
Plane top = new Plane(Vector3.up, Vector3.up / 2f);
Plane bottom = new Plane(-Vector3.up, -Vector3.up / 2f);
Plane front = new Plane(Vector3.forward, Vector3.forward / 2f);
Plane back = new Plane(-Vector3.forward, -Vector3.forward / 2f);
Vector3[] vertices = affectedMesh.vertices;
int[] triangles = affectedMesh.triangles;
int startVertexCount = _bufVertices.Count;
Matrix4x4 matrix = decal.transform.worldToLocalMatrix * affectedObject.transform.localToWorldMatrix;
for (int i = 0; i < triangles.Length; i += 3)
{
int i1 = triangles[i];
int i2 = triangles[i + 1];
int i3 = triangles[i + 2];
Vector3 v1 = matrix.MultiplyPoint(vertices[i1]);
Vector3 v2 = matrix.MultiplyPoint(vertices[i2]);
Vector3 v3 = matrix.MultiplyPoint(vertices[i3]);
Vector3 side1 = v2 - v1;
Vector3 side2 = v3 - v1;
Vector3 normal = Vector3.Cross(side1, side2).normalized;
if (Vector3.Angle(-Vector3.forward, normal) >= maxAngle)
{
continue;
}
DecalPolygon poly = new DecalPolygon(v1, v2, v3);
poly = DecalPolygon.ClipPolygon(poly, right);
if (poly == null)
{
continue;
}
poly = DecalPolygon.ClipPolygon(poly, left);
if (poly == null)
{
continue;
}
poly = DecalPolygon.ClipPolygon(poly, top);
if (poly == null)
{
continue;
}
poly = DecalPolygon.ClipPolygon(poly, bottom);
if (poly == null)
{
continue;
}
poly = DecalPolygon.ClipPolygon(poly, front);
if (poly == null)
{
continue;
}
poly = DecalPolygon.ClipPolygon(poly, back);
if (poly == null)
{
continue;
}
AddPolygon(poly, normal);
}
if (decal.Sprite)
{
GenerateTexCoords(startVertexCount, decal.Sprite);
}
else
{
int textureWidth = decal.Material.mainTexture.width;
int textureHeight = decal.Material.mainTexture.height;
Texture2D textureData = new Texture2D(textureWidth, textureHeight);
Sprite.Create(textureData, new Rect(0, 0, textureWidth, textureHeight), new Vector2(textureWidth / 2, textureHeight / 2));
GenerateTexCoords(startVertexCount, decal.Sprite);
}
}