Are there mesh building helper classes in WPF or .NET 4.0?
The mechanisms for building a mesh in WPF are quite low-level. For exam开发者_运维问答ple you have to supply the vertexes and the indexes. Are there helpers in the WPF or anywhere in the .NET 4.0 framework I can use? Or do I have to resort to third party libraries?
Here's an older chunk of XNA 3.1 code I wrote to build a Sphere. I apply a transformation matrix in my rendering loop that allows me to stretch and orient it. Computing the vertices is fairly straightforward... computing the indices are what I find more difficult. This should hopefully give you an idea, though. The other primitives (e.g. cone, cylinder, cube...) are much simpler to compute.
The m_iSegments paremeter just allows me to define how many slices I want to divide the sphere into... the more segments, the more vertices, the smoother the sphere.
The m_Appearance parameter is my wrapper for the shader.
/// <summary>
/// This method constructs ellipsoid vertices, indices, and normals.
/// Equations are performed using the parameterized equations:
///
/// x = a cos(B)cos(L)
/// y = b cos(B)sin(L)
/// z = c sin(B)
///
/// Where:
///
/// B = latitude and,
/// L = longitude
///
/// </summary>
/// <seealso cref="http://en.wikipedia.org/wiki/Ellipsoid">Wikipedia - Ellipsoid</seealso>
public override void BuildVertices()
{
#region Declarations
int iIndex = 0; // Stores the index of the vertex array.
int iBeta = 0; // Stores the beta increment.
int iLambda = 0; // Stores the lambda increment.
float Beta = 0.0f; // Beta0 - Stores the latitude.
float Lambda = 0.0f; // Lambda0 - Stores the longitude.
float BetaStep = MathHelper.Pi / m_iSegments; // Latitude Segements, in degrees.
float LambdaStep = MathHelper.TwoPi / m_iSegments; // Longitude Segments, in degrees.
Vector3 vectPos = Vector3.Zero; // Vertex Position Vector
Vector3 vectNor = Vector3.Zero; // Vertex Normal Vector
Vector2 vectTex = Vector2.Zero; // Vertex Texture Coordinate
#endregion
#region Build the vertices.
int[] iIndices = new int[6 * m_iSegments * m_iSegments];
Vector3[] vVertices = new Vector3[(m_iSegments + 1) * (m_iSegments + 1)];
Vector2[] vTexCrds = new Vector2[vVertices.Length];
iIndex = 0;
for (iBeta = 0; iBeta <= m_iSegments; iBeta++)
{
// Compute the latitude.
Beta = MathHelper.Clamp((-MathHelper.PiOver2) + (iBeta * BetaStep), -MathHelper.PiOver2, MathHelper.PiOver2);
for (iLambda = 0; iLambda <= m_iSegments; iLambda++)
{
// Compute the current longitude.
Lambda = MathHelper.Clamp((-MathHelper.Pi) + (iLambda * LambdaStep), -MathHelper.Pi, MathHelper.Pi);
// Compute the current vertex.
vVertices[iIndex] = new Vector3((float)(Math.Cos(Beta) * Math.Sin(Lambda)),
(float)(Math.Sin(Beta)),
(float)(Math.Cos(Beta) * Math.Cos(Lambda)));
// Compute the triangle indices.
if (iBeta < m_iSegments &&
iLambda < m_iSegments)
{
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 0] = iIndex;
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 1] = iIndex + m_iSegments + 1;
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 2] = iIndex + m_iSegments + 2;
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 3] = iIndex;
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 4] = iIndex + m_iSegments + 2;
iIndices[iIndex + (iIndex * 5) - (iBeta * 6) + 5] = iIndex + 1;
}
// Compute the texture coordinates.
vTexCrds[iIndex] = new Vector2((float)iLambda / (float)m_iSegments, 1.0f - (float)iBeta / (float)m_iSegments);
iIndex++;
}
}
# endregion
#region Build the normals.
Vector3[] vNormals = new Vector3[vVertices.Length];
for (iIndex = 0; iIndex < vVertices.Length; iIndex++)
{
vNormals[iIndex] = vVertices[iIndex] - this.AbsolutePosition;
vNormals[iIndex].Normalize();
}
#endregion
#region Build the buffers.
VertexPositionNormalTexture[] vertices = new VertexPositionNormalTexture[vVertices.Length];
for (iIndex = 0; iIndex < vVertices.Length; iIndex++)
vertices[iIndex] = new VertexPositionNormalTexture(vVertices[iIndex], vNormals[iIndex], vTexCrds[iIndex]);
m_pAppearance.SetBuffers(vertices, iIndices);
#endregion
}
精彩评论