public static void CreateSolid(this IGeometryBuilder builder, int tessellation)
{
Vector3 offset = new Vector3(0, -0.25f, 0);
builder.AddVertex(Vector3.UnitY + offset, Vector3.UnitY);
builder.AddVertex(Vector3.Zero + offset, -Vector3.UnitY);
for (int i = 0; i < tessellation; ++i)
{
float angle = i * Algorithms.Helpers.TwoPi / tessellation;
float dx = MathF.Cos(angle);
float dz = MathF.Sin(angle);
Vector3 normal = new Vector3(dx, 0, dz);
builder.AddVertex(normal + offset, normal);
builder.AddIndex(0);
builder.AddIndex(2 + i);
builder.AddIndex(2 + (i + 1) % tessellation);
builder.AddIndex(1);
builder.AddIndex(2 + (i + 1) % tessellation);
builder.AddIndex(2 + i);
}
}
public static void CreateSolid(this IGeometryBuilder builder, Vector3 size)
{
for (int i = 0; i < normals.Length; i++)
{
var normal = normals[i];
Vector3 side1 = new Vector3(normal.Y, normal.Z, normal.X);
Vector3 side2 = Vector3.Cross(normal, side1);
builder.AddIndex(builder.CurrentVertex + 0);
builder.AddIndex(builder.CurrentVertex + 1);
builder.AddIndex(builder.CurrentVertex + 2);
builder.AddIndex(builder.CurrentVertex + 0);
builder.AddIndex(builder.CurrentVertex + 2);
builder.AddIndex(builder.CurrentVertex + 3);
builder.AddVertex(((normal - side1 - side2) / 2.0f) * size, normal, Vector2.Zero);
builder.AddVertex(((normal - side1 + side2) / 2.0f) * size, normal, Vector2.UnitX);
builder.AddVertex(((normal + side1 + side2) / 2.0f) * size, normal, Vector2.One);
builder.AddVertex(((normal + side1 - side2) / 2.0f) * size, normal, Vector2.UnitY);
}
}
public static void CreateSolid(this IGeometryBuilder builder, Vector3 start, Vector3 end, float radius, int tessellation)
{
builder.AddVertex(start * 0.5f, start);
builder.AddVertex(-end * 0.5f, -end);
float diameter = radius / 2.0f;
for (int i = 0; i < tessellation; ++i)
{
float angle = i * Algorithms.Helpers.TwoPi / tessellation;
float dx = MathF.Cos(angle);
float dz = MathF.Sin(angle);
Vector3 normal = new Vector3(dx, 0.0f, dz);
builder.AddVertex(normal + (diameter * start), normal);
builder.AddVertex(normal - (diameter * start), normal);
builder.AddIndex(0);
builder.AddIndex(2 + (i * 2));
builder.AddIndex(2 + (((i * 2) + 2) % (tessellation * 2)));
builder.AddIndex(2 + (i * 2));
builder.AddIndex(2 + (i * 2) + 1);
builder.AddIndex(2 + (((i * 2) + 2) % (tessellation * 2)));
builder.AddIndex(1);
builder.AddIndex(2 + (((i * 2) + 3) % (tessellation * 2)));
builder.AddIndex(2 + (i * 2) + 1);
builder.AddIndex(2 + (i * 2) + 1);
builder.AddIndex(2 + (((i * 2) + 3) % (tessellation * 2)));
builder.AddIndex(2 + (((i * 2) + 2) % (tessellation * 2)));
}
}
public static void CreateSolid(this IGeometryBuilder builder, int tessellation)
{
// First we loop around the main ring of the torus.
for (int i = 0; i < tessellation; ++i)
{
float outerAngle = i * Algorithms.Helpers.TwoPi / tessellation;
// Create a transform matrix that will align geometry to
// slice perpendicularly though the current ring position.
var transform = Matrix4x4.CreateTranslation(1, 0, 0) *
Matrix4x4.CreateRotationY(outerAngle);
// Now we loop along the other axis, around the side of the tube.
for (int j = 0; j < tessellation; j++)
{
float innerAngle = j * Algorithms.Helpers.TwoPi / tessellation;
float dx = MathF.Cos(innerAngle);
float dy = MathF.Sin(innerAngle);
// Create a vertex.
Vector3 normal = new Vector3(dx, dy, 0);
Vector3 position = normal / 2.0f;
position = Vector3.Transform(position, transform);
normal = Vector3.TransformNormal(normal, transform);
builder.AddVertex(position, normal);
// And create indices for two triangles.
int nextI = (i + 1) % tessellation;
int nextJ = (j + 1) % tessellation;
builder.AddIndex(i * tessellation + j);
builder.AddIndex(i * tessellation + nextJ);
builder.AddIndex(nextI * tessellation + j);
builder.AddIndex(i * tessellation + nextJ);
builder.AddIndex(nextI * tessellation + nextJ);
builder.AddIndex(nextI * tessellation + j);
}
}
}
public static void CreateSolid(this IGeometryBuilder builder, float radius, int tessellation)
{
int verticalSegments = tessellation;
int horizontalSegments = tessellation * 2;
// Start with a single vertex at the bottom of the sphere.
builder.AddVertex(Vector3.UnitY, -Vector3.UnitY);
// Create rings of vertices at progressively higher latitudes.
for (int i = 0; i < verticalSegments - 1; ++i)
{
float latitude = ((i + 1.0f) * Algorithms.Helpers.Pi / verticalSegments) - Algorithms.Helpers.PiOver2;
float dy = MathF.Sin(latitude);
float dxz = MathF.Cos(latitude);
// Create a single ring of vertices at this latitude.
for (int j = 0; j < horizontalSegments; j++)
{
float longitude = j * Algorithms.Helpers.TwoPi / horizontalSegments;
float dx = MathF.Cos(longitude) * dxz;
float dz = MathF.Sin(longitude) * dxz;
Vector3 normal = new Vector3(dx, dy, dz) * radius;
builder.AddVertex(normal, normal);
}
}
// Finish with a single vertex at the top of the sphere.
builder.AddVertex(Vector3.UnitY, Vector3.UnitY);
// Create a fan connecting the bottom vertex to the bottom latitude ring.
for (int i = 0; i < horizontalSegments; ++i)
{
builder.AddIndex(0);
builder.AddIndex(1 + ((i + 1) % horizontalSegments));
builder.AddIndex(1 + i);
}
// Fill the sphere body with triangles joining each pair of latitude rings.
for (int i = 0; i < verticalSegments - 2; ++i)
{
for (int j = 0; j < horizontalSegments; j++)
{
int nextI = i + 1;
int nextJ = (j + 1) % horizontalSegments;
builder.AddIndex(1 + (i * horizontalSegments) + j);
builder.AddIndex(1 + (i * horizontalSegments) + nextJ);
builder.AddIndex(1 + (nextI * horizontalSegments) + j);
builder.AddIndex(1 + (i * horizontalSegments) + nextJ);
builder.AddIndex(1 + (nextI * horizontalSegments) + nextJ);
builder.AddIndex(1 + (nextI * horizontalSegments) + j);
}
}
// Create a fan connecting the top vertex to the top latitude ring.
for (int i = 0; i < horizontalSegments; ++i)
{
builder.AddIndex(builder.CurrentVertex - 1);
builder.AddIndex(builder.CurrentVertex - 2 - ((i + 1) % horizontalSegments));
builder.AddIndex(builder.CurrentVertex - 2 - i);
}
}
