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 Polygon[] GenerateCylinder(int sideCount = 20)
{
Polygon[] polygons = new Polygon[sideCount * 3];
float angleDelta = Mathf.PI * 2 / sideCount;
for (int i = 0; i < sideCount; i++)
{
polygons[i] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(Mathf.Sin(i * angleDelta), -1, Mathf.Cos(i * angleDelta)),
new Vector3(Mathf.Sin(i * angleDelta), 0, Mathf.Cos(i * angleDelta)),
new Vector2(i * (1f / sideCount), 0)),
new Vertex(new Vector3(Mathf.Sin((i + 1) * angleDelta), -1, Mathf.Cos((i + 1) * angleDelta)),
new Vector3(Mathf.Sin((i + 1) * angleDelta), 0, Mathf.Cos((i + 1) * angleDelta)),
new Vector2((i + 1) * (1f / sideCount), 0)),
new Vertex(new Vector3(Mathf.Sin((i + 1) * angleDelta), 1, Mathf.Cos((i + 1) * angleDelta)),
new Vector3(Mathf.Sin((i + 1) * angleDelta), 0, Mathf.Cos((i + 1) * angleDelta)),
new Vector2((i + 1) * (1f / sideCount), 1)),
new Vertex(new Vector3(Mathf.Sin(i * angleDelta), 1, Mathf.Cos(i * angleDelta)),
new Vector3(Mathf.Sin(i * angleDelta), 0, Mathf.Cos(i * angleDelta)),
new Vector2(i * (1f / sideCount), 1)),
}, null, false, false);
}
Vertex capCenterVertex = new Vertex(new Vector3(0, 1, 0), Vector3.up, new Vector2(0, 0));
for (int i = 0; i < sideCount; i++)
{
Vertex vertex1 = new Vertex(new Vector3(Mathf.Sin(i * angleDelta), 1, Mathf.Cos(i * angleDelta)), Vector3.up, new Vector2(Mathf.Sin(i * angleDelta), Mathf.Cos(i * angleDelta)));
Vertex vertex2 = new Vertex(new Vector3(Mathf.Sin((i + 1) * angleDelta), 1, Mathf.Cos((i + 1) * angleDelta)), Vector3.up, new Vector2(Mathf.Sin((i + 1) * angleDelta), Mathf.Cos((i + 1) * angleDelta)));
Vertex[] capVertices = new Vertex[] { vertex1, vertex2, capCenterVertex.DeepCopy() };
polygons[sideCount + i] = new Polygon(capVertices, null, false, false);
}
capCenterVertex = new Vertex(new Vector3(0, -1, 0), Vector3.down, new Vector2(0, 0));
for (int i = 0; i < sideCount; i++)
{
Vertex vertex1 = new Vertex(new Vector3(Mathf.Sin(i * -angleDelta), -1, Mathf.Cos(i * -angleDelta)), Vector3.down, new Vector2(Mathf.Sin(i * angleDelta), Mathf.Cos(i * angleDelta)));
Vertex vertex2 = new Vertex(new Vector3(Mathf.Sin((i + 1) * -angleDelta), -1, Mathf.Cos((i + 1) * -angleDelta)), Vector3.down, new Vector2(Mathf.Sin((i + 1) * angleDelta), Mathf.Cos((i + 1) * angleDelta)));
Vertex[] capVertices = new Vertex[] { vertex1, vertex2, capCenterVertex.DeepCopy() };
polygons[sideCount * 2 + i] = new Polygon(capVertices, null, false, false);
}
return(polygons);
}
/// <summary>
/// Adapted from GetUVForPosition
/// </summary>
public static Vertex GetVertexForPosition(Vertex vertex1, Vertex vertex2, Vertex vertex3,
Vector3 newPosition)
{
Vector3 pos1 = vertex1.Position;
Vector3 pos2 = vertex2.Position;
Vector3 pos3 = vertex3.Position;
//Plane plane = new Plane(pos1,pos2,pos3); // TODO Is it safe to replace this with the polygon Plane property?
//Vector3 planePoint = MathHelper.ClosestPointOnPlane(newPosition, plane);
Vector3 planePoint = newPosition;
// calculate vectors from point f to vertices p1, p2 and p3:
Vector3 f1 = pos1 - planePoint;
Vector3 f2 = pos2 - planePoint;
Vector3 f3 = pos3 - planePoint;
// calculate the areas (parameters order is essential in this case):
Vector3 va = Vector3.Cross(pos1 - pos2, pos1 - pos3); // main triangle cross product
Vector3 va1 = Vector3.Cross(f2, f3); // p1's triangle cross product
Vector3 va2 = Vector3.Cross(f3, f1); // p2's triangle cross product
Vector3 va3 = Vector3.Cross(f1, f2); // p3's triangle cross product
float a = va.magnitude; // main triangle area
// calculate barycentric coordinates with sign:
float a1 = va1.magnitude / a * Mathf.Sign(Vector3.Dot(va, va1));
float a2 = va2.magnitude / a * Mathf.Sign(Vector3.Dot(va, va2));
float a3 = va3.magnitude / a * Mathf.Sign(Vector3.Dot(va, va3));
Vertex vertex = vertex1.DeepCopy();
// Interpolate normal and UV based on the barycentric coordinates
vertex.Normal = vertex1.Normal * a1 + vertex2.Normal * a2 + vertex3.Normal * a3;
vertex.UV = vertex1.UV * a1 + vertex2.UV * a2 + vertex3.UV * a3;
// Interpolate the color, slightly more complex as need to implicit cast from Color32 to Color and back for interpolation
Color color1 = vertex1.Color;
Color color2 = vertex1.Color;
Color color3 = vertex1.Color;
vertex.Color = color1 * a1 + color2 * a2 + color3 * a3;
return(vertex);
}
/// <summary>
/// Generates a cone of height and radius 2. If the <see cref="sideCount"/> is 3, generates a triangular-based pyramid.
/// </summary>
/// <param name="sideCount">Side count for the cone (if 3, generates a triangular-based pyramid.).</param>
/// <returns>Polygons to be supplied to a brush.</returns>
public static Polygon[] GenerateCone(int sideCount = 20)
{
Polygon[] polygons = new Polygon[sideCount * 2];
// the cone generator will create a slightly distorted off-center output for 3 sides.
// if the user sets the side count to 3 we will generate a triangular-based pyramid.
if (sideCount == 3)
{
polygons = new Polygon[sideCount + 1];
polygons[0] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(0, -1, -1), new Vector3(0.8402f, 0.2425f, -0.4851f), new Vector2(0.0000f, 0.0000f)),
new Vertex(new Vector3(0, 1, 0), new Vector3(0.8402f, 0.2425f, -0.4851f), new Vector2(0.5000f, 1.0000f)),
new Vertex(new Vector3(1, -1, 1), new Vector3(0.8402f, 0.2425f, -0.4851f), new Vector2(1.0000f, 0.0000f)),
}, null, false, false);
polygons[1] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(1, -1, 1), new Vector3(-0.0000f, 0.2425f, 0.9701f), new Vector2(0.0000f, 0.0000f)),
new Vertex(new Vector3(0, 1, 0), new Vector3(-0.0000f, 0.2425f, 0.9701f), new Vector2(0.5000f, 1.0000f)),
new Vertex(new Vector3(-1, -1, 1), new Vector3(-0.0000f, 0.2425f, 0.9701f), new Vector2(1.0000f, 0.0000f)),
}, null, false, false);
polygons[2] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(-1, -1, 1), new Vector3(-0.8402f, 0.2425f, -0.4851f), new Vector2(0.0000f, 0.0000f)),
new Vertex(new Vector3(0, 1, 0), new Vector3(-0.8402f, 0.2425f, -0.4851f), new Vector2(0.5000f, 1.0000f)),
new Vertex(new Vector3(0, -1, -1), new Vector3(-0.8402f, 0.2425f, -0.4851f), new Vector2(1.0000f, 0.0000f)),
}, null, false, false);
polygons[3] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(0, -1, -1), Vector3.down, new Vector2(0.0000f, 0.0000f)),
new Vertex(new Vector3(1, -1, 1), Vector3.down, new Vector2(1.0000f, 1.0000f)),
new Vertex(new Vector3(-1, -1, 1), Vector3.down, new Vector2(1.0000f, 0.0000f)),
}, null, false, false);
return(polygons);
}
float angleDelta = Mathf.PI * 2 / sideCount;
for (int i = 0; i < sideCount; i++)
{
Vector3 normal = new Vector3(Mathf.Sin((i + 0.5f) * angleDelta), 0, Mathf.Cos((i + 0.5f) * angleDelta));
polygons[i] = new Polygon(new Vertex[]
{
new Vertex(new Vector3(Mathf.Sin(i * angleDelta), -1, Mathf.Cos(i * angleDelta)),
normal,
new Vector2(i * (1f / sideCount), 0)),
new Vertex(new Vector3(Mathf.Sin((i + 1) * angleDelta), -1, Mathf.Cos((i + 1) * angleDelta)),
normal,
new Vector2((i + 1) * (1f / sideCount), 0)),
new Vertex(new Vector3(0, 1, 0),
normal,
new Vector2((((i + 1) * (1f / sideCount)) + (i * (1f / sideCount))) / 2.0f, 1.0f)),
}, null, false, false);
}
Vertex capCenterVertex = new Vertex(new Vector3(0, -1, 0), Vector3.down, new Vector2(0, 0));
for (int i = 0; i < sideCount; i++)
{
Vertex vertex1 = new Vertex(new Vector3(Mathf.Sin(i * -angleDelta), -1, Mathf.Cos(i * -angleDelta)), Vector3.down, new Vector2(Mathf.Sin(i * angleDelta), Mathf.Cos(i * angleDelta)));
Vertex vertex2 = new Vertex(new Vector3(Mathf.Sin((i + 1) * -angleDelta), -1, Mathf.Cos((i + 1) * -angleDelta)), Vector3.down, new Vector2(Mathf.Sin((i + 1) * angleDelta), Mathf.Cos((i + 1) * angleDelta)));
Vertex[] capVertices = new Vertex[] { vertex1, vertex2, capCenterVertex.DeepCopy() };
polygons[sideCount + i] = new Polygon(capVertices, null, false, false);
}
return(polygons);
}
/// <summary>
/// Generates an ico-sphere of radius 2. Unlike a polar-sphere this has a more even distribution of vertices.
/// </summary>
/// <returns>Polygons to be supplied to a brush.</returns>
/// <param name="iterationCount">Number of times the surface is subdivided, values of 1 or 2 are recommended.</param>
public static Polygon[] GenerateIcoSphere(int iterationCount)
{
// Derived from http://blog.andreaskahler.com/2009/06/creating-icosphere-mesh-in-code.html
float longestDimension = (1 + Mathf.Sqrt(5f)) / 2f;
Vector3 sourceVector = new Vector3(0, 1, longestDimension);
// Make the longest dimension 1, so the icosphere fits in a 2,2,2 cube
sourceVector.Normalize();
Vertex[] vertices = new Vertex[]
{
new Vertex(new Vector3(-sourceVector.y, +sourceVector.z, sourceVector.x), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.y, +sourceVector.z, sourceVector.x), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(-sourceVector.y, -sourceVector.z, sourceVector.x), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.y, -sourceVector.z, sourceVector.x), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.x, -sourceVector.y, +sourceVector.z), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.x, +sourceVector.y, +sourceVector.z), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.x, -sourceVector.y, -sourceVector.z), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(sourceVector.x, +sourceVector.y, -sourceVector.z), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(+sourceVector.z, sourceVector.x, -sourceVector.y), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(+sourceVector.z, sourceVector.x, +sourceVector.y), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(-sourceVector.z, sourceVector.x, -sourceVector.y), Vector3.zero, Vector2.zero),
new Vertex(new Vector3(-sourceVector.z, sourceVector.x, +sourceVector.y), Vector3.zero, Vector2.zero),
};
Polygon[] polygons = new Polygon[]
{
new Polygon(new Vertex[] { vertices[0].DeepCopy(), vertices[1].DeepCopy(), vertices[7].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[0].DeepCopy(), vertices[5].DeepCopy(), vertices[1].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[0].DeepCopy(), vertices[7].DeepCopy(), vertices[10].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[0].DeepCopy(), vertices[10].DeepCopy(), vertices[11].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[0].DeepCopy(), vertices[11].DeepCopy(), vertices[5].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[7].DeepCopy(), vertices[1].DeepCopy(), vertices[8].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[1].DeepCopy(), vertices[5].DeepCopy(), vertices[9].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[10].DeepCopy(), vertices[7].DeepCopy(), vertices[6].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[11].DeepCopy(), vertices[10].DeepCopy(), vertices[2].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[5].DeepCopy(), vertices[11].DeepCopy(), vertices[4].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[3].DeepCopy(), vertices[2].DeepCopy(), vertices[6].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[3].DeepCopy(), vertices[4].DeepCopy(), vertices[2].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[3].DeepCopy(), vertices[6].DeepCopy(), vertices[8].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[3].DeepCopy(), vertices[8].DeepCopy(), vertices[9].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[3].DeepCopy(), vertices[9].DeepCopy(), vertices[4].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[6].DeepCopy(), vertices[2].DeepCopy(), vertices[10].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[2].DeepCopy(), vertices[4].DeepCopy(), vertices[11].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[8].DeepCopy(), vertices[6].DeepCopy(), vertices[7].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[9].DeepCopy(), vertices[8].DeepCopy(), vertices[1].DeepCopy() }, null, false, false),
new Polygon(new Vertex[] { vertices[4].DeepCopy(), vertices[9].DeepCopy(), vertices[5].DeepCopy() }, null, false, false),
};
// Refine
for (int i = 0; i < iterationCount; i++)
{
Polygon[] newPolygons = new Polygon[polygons.Length * 4];
for (int j = 0; j < polygons.Length; j++)
{
Vertex a = Vertex.Lerp(polygons[j].Vertices[0], polygons[j].Vertices[1], 0.5f);
Vertex b = Vertex.Lerp(polygons[j].Vertices[1], polygons[j].Vertices[2], 0.5f);
Vertex c = Vertex.Lerp(polygons[j].Vertices[2], polygons[j].Vertices[0], 0.5f);
a.Position = a.Position.normalized;
b.Position = b.Position.normalized;
c.Position = c.Position.normalized;
newPolygons[j * 4 + 0] = new Polygon(new Vertex[] { polygons[j].Vertices[0].DeepCopy(), a.DeepCopy(), c.DeepCopy() }, null, false, false);
newPolygons[j * 4 + 1] = new Polygon(new Vertex[] { polygons[j].Vertices[1].DeepCopy(), b.DeepCopy(), a.DeepCopy() }, null, false, false);
newPolygons[j * 4 + 2] = new Polygon(new Vertex[] { polygons[j].Vertices[2].DeepCopy(), c.DeepCopy(), b.DeepCopy() }, null, false, false);
newPolygons[j * 4 + 3] = new Polygon(new Vertex[] { a.DeepCopy(), b.DeepCopy(), c.DeepCopy() }, null, false, false);
}
polygons = newPolygons;
}
for (int i = 0; i < polygons.Length; i++)
{
bool anyAboveHalf = false;
for (int j = 0; j < polygons[i].Vertices.Length; j++)
{
Vector3 normal = polygons[i].Vertices[j].Position.normalized;
polygons[i].Vertices[j].Normal = normal;
float piReciprocal = 1f / Mathf.PI;
float u = 0.5f - 0.5f * Mathf.Atan2(normal.x, -normal.z) * piReciprocal;
float v = 1f - Mathf.Acos(normal.y) * piReciprocal;
if (Mathf.Abs(u) < 0.01f ||
Mathf.Abs(1 - Mathf.Abs(u)) < 0.01f)
{
if (polygons[i].Plane.normal.x > 0)
{
u = 0;
}
else
{
u = 1;
}
}
if (u > 0.75f)
{
anyAboveHalf = true;
}
//Debug.Log(u);
polygons[i].Vertices[j].UV = new Vector2(u, v);
//const float kOneOverPi = 1.0 / 3.14159265;
//float u = 0.5 - 0.5 * atan(N.x, -N.z) * kOneOverPi;
//float v = 1.0 - acos(N.y) * kOneOverPi;
}
if (anyAboveHalf)
{
for (int j = 0; j < polygons[i].Vertices.Length; j++)
{
Vector2 uv = polygons[i].Vertices[j].UV;
if (uv.x < 0.5f)
{
uv.x += 1;
}
polygons[i].Vertices[j].UV = uv;
}
}
}
return(polygons);
}
public static bool SplitPolygon(Polygon polygon, out Polygon frontPolygon, out Polygon backPolygon, out Vertex newVertex1, out Vertex newVertex2, UnityEngine.Plane clipPlane)
{
newVertex1 = null;
newVertex2 = null;
List <Vertex> frontVertices = new List <Vertex>();
List <Vertex> backVertices = new List <Vertex>();
for (int i = 0; i < polygon.vertices.Length; i++)
{
int previousIndex = i - 1;
if (previousIndex < 0)
{
previousIndex = polygon.vertices.Length - 1;
}
Vertex currentVertex = polygon.vertices[i];
Vertex previousVertex = polygon.vertices[previousIndex];
PointPlaneRelation currentRelation = ComparePointToPlane(currentVertex.Position, clipPlane);
PointPlaneRelation previousRelation = ComparePointToPlane(previousVertex.Position, clipPlane);
if (previousRelation == PointPlaneRelation.InFront && currentRelation == PointPlaneRelation.InFront)
{
// Front add current
frontVertices.Add(currentVertex);
}
else if (previousRelation == PointPlaneRelation.Behind && currentRelation == PointPlaneRelation.InFront)
{
float interpolant = Edge.IntersectsPlane(clipPlane, previousVertex.Position, currentVertex.Position);
Vertex intersection = Vertex.Lerp(previousVertex, currentVertex, interpolant);
// Front add intersection, add current
frontVertices.Add(intersection);
frontVertices.Add(currentVertex);
// Back add intersection
backVertices.Add(intersection.DeepCopy());
newVertex2 = intersection;
}
else if (previousRelation == PointPlaneRelation.InFront && currentRelation == PointPlaneRelation.Behind)
{
// Reverse order here so that clipping remains consistent for either CW or CCW testing
float interpolant = Edge.IntersectsPlane(clipPlane, currentVertex.Position, previousVertex.Position);
Vertex intersection = Vertex.Lerp(currentVertex, previousVertex, interpolant);
// Front add intersection
frontVertices.Add(intersection);
// Back add intersection, current
backVertices.Add(intersection.DeepCopy());
backVertices.Add(currentVertex);
newVertex1 = intersection;
}
else if (previousRelation == PointPlaneRelation.Behind && currentRelation == PointPlaneRelation.Behind)
{
// Back add current
backVertices.Add(currentVertex);
}
else if (currentRelation == PointPlaneRelation.On)
{
// Front add current
frontVertices.Add(currentVertex);
// Back add current
backVertices.Add(currentVertex.DeepCopy());
if (previousRelation == PointPlaneRelation.InFront)
{
newVertex1 = currentVertex;
}
else if (previousRelation == PointPlaneRelation.Behind)
{
newVertex2 = currentVertex;
}
else
{
// throw new System.Exception("Unhandled polygon configuration");
}
}
else if (currentRelation == PointPlaneRelation.Behind)
{
backVertices.Add(currentVertex);
}
else if (currentRelation == PointPlaneRelation.InFront)
{
frontVertices.Add(currentVertex);
}
else
{
throw new System.Exception("Unhandled polygon configuration");
}
}
// Debug.Log("done");
frontPolygon = new Polygon(frontVertices.ToArray(), polygon.Material, polygon.ExcludeFromFinal, polygon.UserExcludeFromFinal, polygon.uniqueIndex);
backPolygon = new Polygon(backVertices.ToArray(), polygon.Material, polygon.ExcludeFromFinal, polygon.UserExcludeFromFinal, polygon.uniqueIndex);
// Because of some floating point issues and some edge cases relating to splitting the tip of a very thin
// polygon we can't reliable test that the polygon intersects a plane and will produce two valid pieces
// so after splitting we need to do an additional test to check that each polygon is valid. If it isn't
// then we mark that polygon as null and return false to indicate the split wasn't entirely successful
bool splitNecessary = true;
if (frontPolygon.vertices.Length < 3 || frontPolygon.Plane.normal == Vector3.zero)
{
frontPolygon = null;
splitNecessary = false;
}
if (backPolygon.vertices.Length < 3 || backPolygon.Plane.normal == Vector3.zero)
{
backPolygon = null;
splitNecessary = false;
}
return(splitNecessary);
}
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();
}
