public CMeshData CreateSphere(SCreateSphereCmd cmd)
{
// output data
List<FatVertex> vb = new List<FatVertex>();
List<int> ib = new List<int>();
// main vertices
FatVertex topVertex = new FatVertex()
{
Position = new Vector4(0.0f, cmd.Radius, 0.0f, 1.0f)
};
FatVertex btmVertex = new FatVertex()
{
Position = new Vector4(0.0f, -cmd.Radius, 0.0f, 1.0f)
};
vb.Add(topVertex);
float phiStep = (float)(Math.PI / cmd.StackCount);
float thetaStep = (float)(2.0f * Math.PI / cmd.SlicesCount);
// Compute vertices for each stack ring (do not count the poles as rings)
for (int i = 1; i <= cmd.StackCount - 1; ++i)
{
float phi = phiStep * i;
// Vertices of ring
for (int j = 0; j <= cmd.SlicesCount; ++j)
{
float theta = thetaStep * j;
FatVertex v = new FatVertex();
// spherical to cartesian
v.Position.X = (float)(cmd.Radius * Math.Sin(phi) * Math.Cos(theta));
v.Position.Y = (float)(cmd.Radius * Math.Cos(phi));
v.Position.Z = (float)(cmd.Radius * Math.Sin(phi) * Math.Sin(theta));
v.Position.W = 1.0f;
// calculate tangent (1st degree partial derivative of theta (fixed y))
Vector3 tangent;
tangent.X = (float)(-cmd.Radius * Math.Sin(phi) * Math.Sin(theta));
tangent.Y = (float)(0.0f);
tangent.Z = (float)( cmd.Radius * Math.Sin(phi) * Math.Cos(theta));
tangent.Normalize();
// normal is basically our normalized position
v.Normal = v.Position;
v.Normal.W = 0.0f;
v.Normal.Normalize();
// uv coord
v.TexCoord0.X = (float)(theta / (2.0f * Math.PI));
v.TexCoord0.Y = (float)(phi / (Math.PI));
vb.Add(v);
}
}
vb.Add(btmVertex);
// indices generator (Quad based)
// compute indices for the top stack
for (int i = 1; i <= cmd.SlicesCount; ++i)
{
ib.Add(0);
ib.Add(0);
ib.Add(i);
ib.Add(i + 1);
}
// offset indices to the first ring (skipping the north pole vertex)
int baseIndex = 1; // skipping the top pole
int ringVertexCount = cmd.SlicesCount + 1;
for (int i = 0; i < cmd.StackCount - 2; ++i)
{
for (int j = 0; j < cmd.SlicesCount; ++j)
{
ib.Add(baseIndex + i * ringVertexCount + j);
ib.Add(baseIndex + i * ringVertexCount + (j + 1));
ib.Add(baseIndex + (i + 1) * ringVertexCount + j);
ib.Add(baseIndex + (i + 1) * ringVertexCount + (j + 1));
}
}
// now the bottom ring
int southPoleIndex = vb.Count - 1; // the last vertex in the list is the bottom pole
baseIndex = southPoleIndex - ringVertexCount;
for (int i = 0; i < cmd.SlicesCount; ++i)
{
ib.Add(baseIndex + i);
ib.Add(baseIndex + (i + 1));
ib.Add(southPoleIndex);
ib.Add(southPoleIndex);
}
// return mesh data
var meshData = new CMeshData()
{
VB = new DataStream(vb.ToArray(), false, false),
IB = new DataStream(ib.ToArray(), false, false),
IndexCount = ib.Count
};
return meshData;
}
public CMeshData CreateSphere(SCreateSphereCmd cmd)
{
// output data
List <FatVertex> vb = new List <FatVertex>();
List <int> ib = new List <int>();
// main vertices
FatVertex topVertex = new FatVertex()
{
Position = new Vector4(0.0f, cmd.Radius, 0.0f, 1.0f)
};
FatVertex btmVertex = new FatVertex()
{
Position = new Vector4(0.0f, -cmd.Radius, 0.0f, 1.0f)
};
vb.Add(topVertex);
float phiStep = (float)(Math.PI / cmd.StackCount);
float thetaStep = (float)(2.0f * Math.PI / cmd.SlicesCount);
// Compute vertices for each stack ring (do not count the poles as rings)
for (int i = 1; i <= cmd.StackCount - 1; ++i)
{
float phi = phiStep * i;
// Vertices of ring
for (int j = 0; j <= cmd.SlicesCount; ++j)
{
float theta = thetaStep * j;
FatVertex v = new FatVertex();
// spherical to cartesian
v.Position.X = (float)(cmd.Radius * Math.Sin(phi) * Math.Cos(theta));
v.Position.Y = (float)(cmd.Radius * Math.Cos(phi));
v.Position.Z = (float)(cmd.Radius * Math.Sin(phi) * Math.Sin(theta));
v.Position.W = 1.0f;
// calculate tangent (1st degree partial derivative of theta (fixed y))
Vector3 tangent;
tangent.X = (float)(-cmd.Radius * Math.Sin(phi) * Math.Sin(theta));
tangent.Y = (float)(0.0f);
tangent.Z = (float)(cmd.Radius * Math.Sin(phi) * Math.Cos(theta));
tangent.Normalize();
// normal is basically our normalized position
v.Normal = v.Position;
v.Normal.W = 0.0f;
v.Normal.Normalize();
// uv coord
v.TexCoord0.X = (float)(theta / (2.0f * Math.PI));
v.TexCoord0.Y = (float)(phi / (Math.PI));
vb.Add(v);
}
}
vb.Add(btmVertex);
// indices generator (Quad based)
// compute indices for the top stack
for (int i = 1; i <= cmd.SlicesCount; ++i)
{
ib.Add(0);
ib.Add(0);
ib.Add(i);
ib.Add(i + 1);
}
// offset indices to the first ring (skipping the north pole vertex)
int baseIndex = 1; // skipping the top pole
int ringVertexCount = cmd.SlicesCount + 1;
for (int i = 0; i < cmd.StackCount - 2; ++i)
{
for (int j = 0; j < cmd.SlicesCount; ++j)
{
ib.Add(baseIndex + i * ringVertexCount + j);
ib.Add(baseIndex + i * ringVertexCount + (j + 1));
ib.Add(baseIndex + (i + 1) * ringVertexCount + j);
ib.Add(baseIndex + (i + 1) * ringVertexCount + (j + 1));
}
}
// now the bottom ring
int southPoleIndex = vb.Count - 1; // the last vertex in the list is the bottom pole
baseIndex = southPoleIndex - ringVertexCount;
for (int i = 0; i < cmd.SlicesCount; ++i)
{
ib.Add(baseIndex + i);
ib.Add(baseIndex + (i + 1));
ib.Add(southPoleIndex);
ib.Add(southPoleIndex);
}
// return mesh data
var meshData = new CMeshData()
{
VB = new DataStream(vb.ToArray(), false, false),
IB = new DataStream(ib.ToArray(), false, false),
IndexCount = ib.Count
};
return(meshData);
}
