public static bool SplitPolygonAtEdge(Polygon polygon, Edge edge, out Vertex newVertex)
{
newVertex = null;
List <Vertex> vertices = new List <Vertex>(polygon.Vertices);
for (int i = 0; i < polygon.Vertices.Length; i++)
{
Vector3 position1 = polygon.Vertices[i].Position;
Vector3 position2 = polygon.Vertices[(i + 1) % polygon.Vertices.Length].Position;
if ((edge.Vertex1.Position.EqualsWithEpsilon(position1) && edge.Vertex2.Position.EqualsWithEpsilon(position2)) ||
(edge.Vertex1.Position.EqualsWithEpsilon(position2) && edge.Vertex2.Position.EqualsWithEpsilon(position1)))
{
newVertex = Vertex.Lerp(polygon.Vertices[i], polygon.Vertices[(i + 1) % polygon.Vertices.Length], 0.5f);
vertices.Insert(i + 1, newVertex);
break;
}
}
if (vertices.Count == polygon.Vertices.Length)
{
// Could not add vertex to adjacent polygon
return(false);
}
polygon.SetVertices(vertices.ToArray());
return(true);
}
public static void ExtrudePolygonOld(Polygon sourcePolygon, out Polygon[] outputPolygons, out Quaternion rotation)
{
float extrusionDistance = 1;
Polygon newPolygon = sourcePolygon.DeepCopy();
newPolygon.UniqueIndex = -1;
newPolygon.Flip();
Vector3 normal = sourcePolygon.Plane.normal;
Polygon oppositePolygon = sourcePolygon.DeepCopy();
oppositePolygon.UniqueIndex = -1;
Vertex[] vertices = oppositePolygon.Vertices;
for (int i = 0; i < vertices.Length; i++)
{
vertices[i].Position += normal;
}
oppositePolygon.SetVertices(vertices);
Polygon[] brushSides = new Polygon[sourcePolygon.Vertices.Length];
for (int i = 0; i < newPolygon.Vertices.Length; i++)
{
Vertex vertex1 = newPolygon.Vertices[i].DeepCopy();
Vertex vertex2 = newPolygon.Vertices[(i + 1) % newPolygon.Vertices.Length].DeepCopy();
Vector2 uvDelta = vertex2.UV - vertex1.UV;
float sourceDistance = Vector3.Distance(vertex1.Position, vertex2.Position);
Vector2 rotatedUVDelta = uvDelta.Rotate(90) * (extrusionDistance / sourceDistance);
Vertex vertex3 = vertex1.DeepCopy();
vertex3.Position += normal * extrusionDistance;
vertex3.UV += rotatedUVDelta;
Vertex vertex4 = vertex2.DeepCopy();
vertex4.Position += normal * extrusionDistance;
vertex4.UV += rotatedUVDelta;
Vertex[] newVertices = new Vertex[] { vertex1, vertex2, vertex4, vertex3 };
brushSides[i] = new Polygon(newVertices, sourcePolygon.Material, false, false);
brushSides[i].Flip();
brushSides[i].ResetVertexNormals();
}
List <Polygon> polygons = new List <Polygon>();
polygons.Add(newPolygon);
polygons.Add(oppositePolygon);
polygons.AddRange(brushSides);
outputPolygons = polygons.ToArray();
rotation = Quaternion.identity;
}
public static void ExtrudePolygon(Polygon sourcePolygon, out Polygon[] outputPolygons, out Quaternion rotation)
{
float extrusionDistance = 1;
Polygon basePolygon = sourcePolygon.DeepCopy();
basePolygon.UniqueIndex = -1;
rotation = Quaternion.LookRotation(basePolygon.Plane.normal);
Quaternion cancellingRotation = Quaternion.Inverse(rotation);
Vertex[] vertices = basePolygon.Vertices;
// Vector3 offsetPosition = vertices[0].Position;
for (int i = 0; i < vertices.Length; i++)
{
// vertices[i].Position -= offsetPosition;
vertices[i].Position = cancellingRotation * vertices[i].Position;
vertices[i].Normal = cancellingRotation * vertices[i].Normal;
}
// Vector3 newOffsetPosition = vertices[0].Position;
// Vector3 delta = newOffsetPosition - offsetPosition;
// for (int i = 0; i < vertices.Length; i++)
// {
// vertices[i].Position += delta;
// }
basePolygon.SetVertices(vertices);
Vector3 normal = basePolygon.Plane.normal;
Polygon oppositePolygon = basePolygon.DeepCopy();
oppositePolygon.UniqueIndex = -1;
basePolygon.Flip();
vertices = oppositePolygon.Vertices;
for (int i = 0; i < vertices.Length; i++)
{
vertices[i].Position += normal;
}
oppositePolygon.SetVertices(vertices);
Polygon[] brushSides = new Polygon[sourcePolygon.Vertices.Length];
for (int i = 0; i < basePolygon.Vertices.Length; i++)
{
Vertex vertex1 = basePolygon.Vertices[i].DeepCopy();
Vertex vertex2 = basePolygon.Vertices[(i + 1) % basePolygon.Vertices.Length].DeepCopy();
Vector2 uvDelta = vertex2.UV - vertex1.UV;
float sourceDistance = Vector3.Distance(vertex1.Position, vertex2.Position);
Vector2 rotatedUVDelta = uvDelta.Rotate(90) * (extrusionDistance / sourceDistance);
Vertex vertex3 = vertex1.DeepCopy();
vertex3.Position += normal * extrusionDistance;
vertex3.UV += rotatedUVDelta;
Vertex vertex4 = vertex2.DeepCopy();
vertex4.Position += normal * extrusionDistance;
vertex4.UV += rotatedUVDelta;
Vertex[] newVertices = new Vertex[] { vertex1, vertex2, vertex4, vertex3 };
brushSides[i] = new Polygon(newVertices, sourcePolygon.Material, false, false);
brushSides[i].Flip();
brushSides[i].ResetVertexNormals();
}
List <Polygon> polygons = new List <Polygon>();
polygons.Add(basePolygon);
polygons.Add(oppositePolygon);
polygons.AddRange(brushSides);
outputPolygons = polygons.ToArray();
}
/// <summary>
/// Creates a brush by extruding a supplied polygon by a specified extrusion distance.
/// </summary>
/// <param name="sourcePolygon">Source polygon, typically transformed into world space.</param>
/// <param name="extrusionDistance">Extrusion distance, this is the height (or depth) of the created geometry perpendicular to the source polygon.</param>
/// <param name="outputPolygons">Output brush polygons.</param>
/// <param name="rotation">The rotation to be supplied to the new brush transform.</param>
public static void ExtrudePolygon(Polygon sourcePolygon, float extrusionDistance, out Polygon[] outputPolygons, out Quaternion rotation)
{
bool flipped = false;
if (extrusionDistance < 0)
{
sourcePolygon.Flip();
extrusionDistance = -extrusionDistance;
flipped = true;
}
// Create base polygon
Polygon basePolygon = sourcePolygon.DeepCopy();
basePolygon.UniqueIndex = -1;
rotation = Quaternion.LookRotation(basePolygon.Plane.normal);
Quaternion cancellingRotation = Quaternion.Inverse(rotation);
Vertex[] vertices = basePolygon.Vertices;
for (int i = 0; i < vertices.Length; i++)
{
vertices[i].Position = cancellingRotation * vertices[i].Position;
vertices[i].Normal = cancellingRotation * vertices[i].Normal;
}
basePolygon.SetVertices(vertices);
// Create the opposite polygon by duplicating the base polygon, offsetting and flipping
Vector3 normal = basePolygon.Plane.normal;
Polygon oppositePolygon = basePolygon.DeepCopy();
oppositePolygon.UniqueIndex = -1;
basePolygon.Flip();
vertices = oppositePolygon.Vertices;
for (int i = 0; i < vertices.Length; i++)
{
vertices[i].Position += normal * extrusionDistance;
// vertices[i].UV.x *= -1; // Flip UVs
}
oppositePolygon.SetVertices(vertices);
// Now create each of the brush side polygons
Polygon[] brushSides = new Polygon[sourcePolygon.Vertices.Length];
for (int i = 0; i < basePolygon.Vertices.Length; i++)
{
Vertex vertex1 = basePolygon.Vertices[i].DeepCopy();
Vertex vertex2 = basePolygon.Vertices[(i + 1) % basePolygon.Vertices.Length].DeepCopy();
// Create new UVs for the sides, otherwise we'll get distortion
float sourceDistance = Vector3.Distance(vertex1.Position, vertex2.Position);
float uvDistance = Vector2.Distance(vertex1.UV, vertex2.UV);
float uvScale = sourceDistance / uvDistance;
vertex1.UV = Vector2.zero;
if (flipped)
{
vertex2.UV = new Vector2(-sourceDistance / uvScale, 0);
}
else
{
vertex2.UV = new Vector2(sourceDistance / uvScale, 0);
}
Vector2 uvDelta = vertex2.UV - vertex1.UV;
Vector2 rotatedUVDelta = uvDelta.Rotate(90) * (extrusionDistance / sourceDistance);
Vertex vertex3 = vertex1.DeepCopy();
vertex3.Position += normal * extrusionDistance;
vertex3.UV += rotatedUVDelta;
Vertex vertex4 = vertex2.DeepCopy();
vertex4.Position += normal * extrusionDistance;
vertex4.UV += rotatedUVDelta;
Vertex[] newVertices = new Vertex[] { vertex1, vertex2, vertex4, vertex3 };
brushSides[i] = new Polygon(newVertices, sourcePolygon.Material, false, false);
brushSides[i].Flip();
brushSides[i].ResetVertexNormals();
}
List <Polygon> polygons = new List <Polygon>();
polygons.Add(basePolygon);
polygons.Add(oppositePolygon);
polygons.AddRange(brushSides);
outputPolygons = polygons.ToArray();
}