/// <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);
}
/// <summary>
/// Generates a sphere of radius 2
/// </summary>
/// <returns>Polygons to be supplied to a brush.</returns>
/// <param name="lateralCount">Vertex count up from the south pole to the north pole.</param>
/// <param name="longitudinalCount">Vertex count around the sphere equator.</param>
public static Polygon[] GeneratePolarSphere(int lateralCount = 6, int longitudinalCount = 12)
{
Polygon[] polygons = new Polygon[lateralCount * longitudinalCount];
float angleDelta = 1f / lateralCount;
float longitudinalDelta = 1f / longitudinalCount;
// Generate tris for the top and bottom, then quads for the rest
for (int i = 0; i < lateralCount; i++)
{
for (int j = 0; j < longitudinalCount; j++)
{
Vertex[] vertices;
if (i == lateralCount - 1)
{
vertices = new Vertex[] {
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2(i * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2((i + 1) * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector2(i * (1f / lateralCount), j * (1f / longitudinalCount))),
};
}
else if (i > 0)
{
vertices = new Vertex[] {
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2(i * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2((i + 1) * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector2((i + 1) * (1f / lateralCount), j * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector2(i * (1f / lateralCount), j * (1f / longitudinalCount))),
};
}
else // i == 0
{
vertices = new Vertex[] {
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * i * angleDelta),
Mathf.Sin(Mathf.PI * i * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2(i * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * (j + 1) * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * (j + 1) * longitudinalDelta)
),
new Vector2((i + 1) * (1f / lateralCount), (j + 1) * (1f / longitudinalCount))),
new Vertex(new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector3(Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Cos(2 * Mathf.PI * j * longitudinalDelta),
Mathf.Cos(Mathf.PI * (i + 1) * angleDelta),
Mathf.Sin(Mathf.PI * (i + 1) * angleDelta) * Mathf.Sin(2 * Mathf.PI * j * longitudinalDelta)
),
new Vector2((i + 1) * (1f / lateralCount), j * (1f / longitudinalCount))),
};
}
for (int d = 0; d < vertices.Length; d++)
{
vertices[d].UV = new Vector2(vertices[d].UV.y, 1 - vertices[d].UV.x);
}
polygons[i + j * lateralCount] = new Polygon(vertices, null, false, false);
}
}
return(polygons);
}
/// <summary>
/// Exports the supplied polygons to a OBJ format string, typically you'll use ExportToFile rather than ExportToString
/// </summary>
/// <returns>The OBJ file contents.</returns>
/// <param name="transform">If a transform is provided, the vertex positions and normals are converted from world space to local to the transform.</param>
/// <param name="polygons">Polygons to export.</param>
/// <param name="defaultMaterial">Default material to use if none present on polygon.</param>
public static string ExportToString(Transform transform, List <Polygon> polygons, Material defaultMaterial)
{
// If a transform is provided, convert the world positions and normals to local to the transform
if (transform != null)
{
for (int polygonIndex = 0; polygonIndex < polygons.Count; polygonIndex++)
{
Polygon polygon = polygons[polygonIndex];
for (int vertexIndex = 0; vertexIndex < polygon.Vertices.Length; vertexIndex++)
{
Vertex vertex = polygon.Vertices[vertexIndex];
vertex.Position = transform.InverseTransformPoint(vertex.Position);
vertex.Normal = transform.InverseTransformDirection(vertex.Normal);
}
}
}
// Create polygon subsets for each material
Dictionary <Material, List <Polygon> > polygonMaterialTable = new Dictionary <Material, List <Polygon> >();
// Iterate through every polygon adding it to the appropiate material list
foreach (Polygon polygon in polygons)
{
if (polygon.UserExcludeFromFinal)
{
continue;
}
Material material = polygon.Material;
if (material == null)
{
material = defaultMaterial;
}
if (!polygonMaterialTable.ContainsKey(material))
{
polygonMaterialTable.Add(material, new List <Polygon>());
}
polygonMaterialTable[material].Add(polygon);
}
// Use a string builder as this should allow faster concatenation
StringBuilder stringBuilder = new StringBuilder();
OBJVertexList vertexList = new OBJVertexList();
int positionIndexOffset = 0;
int uvIndexOffset = 0;
int normalIndexOffset = 0;
int meshIndex = 1;
// Create a separate mesh for polygons of each material so that we batch by material
foreach (KeyValuePair <Material, List <Polygon> > polygonMaterialGroup in polygonMaterialTable)
{
List <List <OBJFaceVertex> > faces = new List <List <OBJFaceVertex> >(polygonMaterialGroup.Value.Count);
// Iterate through every polygon and triangulate
foreach (Polygon polygon in polygonMaterialGroup.Value)
{
List <OBJFaceVertex> faceVertices = new List <OBJFaceVertex>(polygon.Vertices.Length);
for (int i = 0; i < polygon.Vertices.Length; i++)
{
OBJFaceVertex faceVertex = vertexList.AddOrGet(polygon.Vertices[i]);
faceVertices.Add(faceVertex);
}
faces.Add(faceVertices);
}
List <Vector3> positions = vertexList.Positions;
List <Vector2> uvs = vertexList.UVs;
List <Vector3> normals = vertexList.Normals;
// Start a new group for the mesh
stringBuilder.AppendLine("g Mesh" + meshIndex);
// Write all the positions
stringBuilder.AppendLine("# Vertex Positions: " + (positions.Count));
for (int i = 0; i < positions.Count; i++)
{
stringBuilder.AppendLine("v " + WriteVector3(positions[i]));
}
// Write all the texture coordinates (UVs)
stringBuilder.AppendLine("# Vertex UVs: " + (uvs.Count));
for (int i = 0; i < uvs.Count; i++)
{
stringBuilder.AppendLine("vt " + WriteVector2(uvs[i]));
}
// Write all the normals
stringBuilder.AppendLine("# Vertex Normals: " + (normals.Count));
for (int i = 0; i < normals.Count; i++)
{
stringBuilder.AppendLine("vn " + WriteVector3(normals[i]));
}
// Write all the faces
stringBuilder.AppendLine("# Faces: " + faces.Count);
for (int i = 0; i < faces.Count; i++)
{
stringBuilder.Append("f ");
for (int j = faces[i].Count - 1; j >= 0; j--)
{
stringBuilder.Append((faces[i][j].PositionIndex + positionIndexOffset) + "/" + (faces[i][j].UVIndex + uvIndexOffset) + "/" + (faces[i][j].NormalIndex + normalIndexOffset) + " ");
}
stringBuilder.AppendLine();
}
// Add some padding between this and the next mesh
stringBuilder.AppendLine();
stringBuilder.AppendLine();
meshIndex++;
// Update the offsets so that the next pass only writes new vertex information
positionIndexOffset += positions.Count;
uvIndexOffset += uvs.Count;
normalIndexOffset += normals.Count;
vertexList.ResetForNext();
}
return(stringBuilder.ToString());
}
