/// <summary>
/// Calcular Tangent y Binormal en base a los 3 vertices de un triangulo y la normal del primero de ellos
/// Basado en: http://www.dhpoware.com/demos/d3d9NormalMapping.html
/// </summary>
public static void computeTangentBinormal(BumpMappingVertex v1, BumpMappingVertex v2, BumpMappingVertex v3, out Vector3 tangent, out Vector3 binormal)
{
// Given the 3 vertices (position and texture coordinates) of a triangle
// calculate and return the triangle's tangent vector. The handedness of
// the local coordinate system is stored in tangent.w. The bitangent is
// then: float3 bitangent = cross(normal, tangent.xyz) * tangent.w.
// Create 2 vectors in object space.
//
// edge1 is the vector from vertex positions v1 to v2.
// edge2 is the vector from vertex positions v1 to v3.
Vector3 edge1 = v2.Position - v1.Position;
Vector3 edge2 = v3.Position - v1.Position;
edge1.Normalize();
edge2.Normalize();
// Create 2 vectors in tangent (texture) space that point in the same
// direction as edge1 and edge2 (in object space).
//
// texEdge1 is the vector from texture coordinates texCoord1 to texCoord2.
// texEdge2 is the vector from texture coordinates texCoord1 to texCoord3.
Vector2 texEdge1 = new Vector2(v2.Tu - v1.Tu, v2.Tv - v1.Tv);
Vector2 texEdge2 = new Vector2(v3.Tu - v1.Tu, v3.Tv - v1.Tv);
texEdge1.Normalize();
texEdge2.Normalize();
// These 2 sets of vectors form the following system of equations:
//
// edge1 = (texEdge1.x * tangent) + (texEdge1.y * bitangent)
// edge2 = (texEdge2.x * tangent) + (texEdge2.y * bitangent)
//
// Using matrix notation this system looks like:
//
// [ edge1 ] [ texEdge1.x texEdge1.y ] [ tangent ]
// [ ] = [ ] [ ]
// [ edge2 ] [ texEdge2.x texEdge2.y ] [ bitangent ]
//
// The solution is:
//
// [ tangent ] 1 [ texEdge2.y -texEdge1.y ] [ edge1 ]
// [ ] = ------- [ ] [ ]
// [ bitangent ] det A [-texEdge2.x texEdge1.x ] [ edge2 ]
//
// where:
// [ texEdge1.x texEdge1.y ]
// A = [ ]
// [ texEdge2.x texEdge2.y ]
//
// det A = (texEdge1.x * texEdge2.y) - (texEdge1.y * texEdge2.x)
//
// From this solution the tangent space basis vectors are:
//
// tangent = (1 / det A) * ( texEdge2.y * edge1 - texEdge1.y * edge2)
// bitangent = (1 / det A) * (-texEdge2.x * edge1 + texEdge1.x * edge2)
// normal = cross(tangent, bitangent)
float det = (texEdge1.X * texEdge2.Y) - (texEdge1.Y * texEdge2.X);
if (FastMath.Abs(det) < 0.0001f) // almost equal to zero
{
tangent.X = 1.0f;
tangent.Y = 0.0f;
tangent.Z = 0.0f;
binormal.X = 0.0f;
binormal.Y = 1.0f;
binormal.Z = 0.0f;
}
else
{
det = 1.0f / det;
tangent.X = (texEdge2.Y * edge1.X - texEdge1.Y * edge2.X) * det;
tangent.Y = (texEdge2.Y * edge1.Y - texEdge1.Y * edge2.Y) * det;
tangent.Z = (texEdge2.Y * edge1.Z - texEdge1.Y * edge2.Z) * det;
//tangent.W = 0.0f;
binormal.X = (-texEdge2.X * edge1.X + texEdge1.X * edge2.X) * det;
binormal.Y = (-texEdge2.X * edge1.Y + texEdge1.X * edge2.Y) * det;
binormal.Z = (-texEdge2.X * edge1.Z + texEdge1.X * edge2.Z) * det;
tangent.Normalize();
binormal.Normalize();
}
// Calculate the handedness of the local tangent space.
// The bitangent vector is the cross product between the triangle face
// normal vector and the calculated tangent vector. The resulting bitangent
// vector should be the same as the bitangent vector calculated from the
// set of linear equations above. If they point in different directions
// then we need to invert the cross product calculated bitangent vector.
Vector3 b = Vector3.Cross(v1.Normal, tangent);
float w = Vector3.Dot(b, binormal) < 0.0f ? -1.0f : 1.0f;
binormal = b * w;
}
/// <summary>
/// Calcular Tangent y Binormal en base a los 3 vertices de un triangulo y la normal del primero de ellos
/// Basado en: http://www.dhpoware.com/demos/d3d9NormalMapping.html
/// </summary>
public static void computeTangentBinormal(BumpMappingVertex v1, BumpMappingVertex v2, BumpMappingVertex v3, out Vector3 tangent, out Vector3 binormal)
{
// Given the 3 vertices (position and texture coordinates) of a triangle
// calculate and return the triangle's tangent vector. The handedness of
// the local coordinate system is stored in tangent.w. The bitangent is
// then: float3 bitangent = cross(normal, tangent.xyz) * tangent.w.
// Create 2 vectors in object space.
//
// edge1 is the vector from vertex positions v1 to v2.
// edge2 is the vector from vertex positions v1 to v3.
Vector3 edge1 = v2.Position - v1.Position;
Vector3 edge2 = v3.Position - v1.Position;
edge1.Normalize();
edge2.Normalize();
// Create 2 vectors in tangent (texture) space that point in the same
// direction as edge1 and edge2 (in object space).
//
// texEdge1 is the vector from texture coordinates texCoord1 to texCoord2.
// texEdge2 is the vector from texture coordinates texCoord1 to texCoord3.
Vector2 texEdge1 = new Vector2(v2.Tu - v1.Tu, v2.Tv - v1.Tv);
Vector2 texEdge2 = new Vector2(v3.Tu - v1.Tu, v3.Tv - v1.Tv);
texEdge1.Normalize();
texEdge2.Normalize();
// These 2 sets of vectors form the following system of equations:
//
// edge1 = (texEdge1.x * tangent) + (texEdge1.y * bitangent)
// edge2 = (texEdge2.x * tangent) + (texEdge2.y * bitangent)
//
// Using matrix notation this system looks like:
//
// [ edge1 ] [ texEdge1.x texEdge1.y ] [ tangent ]
// [ ] = [ ] [ ]
// [ edge2 ] [ texEdge2.x texEdge2.y ] [ bitangent ]
//
// The solution is:
//
// [ tangent ] 1 [ texEdge2.y -texEdge1.y ] [ edge1 ]
// [ ] = ------- [ ] [ ]
// [ bitangent ] det A [-texEdge2.x texEdge1.x ] [ edge2 ]
//
// where:
// [ texEdge1.x texEdge1.y ]
// A = [ ]
// [ texEdge2.x texEdge2.y ]
//
// det A = (texEdge1.x * texEdge2.y) - (texEdge1.y * texEdge2.x)
//
// From this solution the tangent space basis vectors are:
//
// tangent = (1 / det A) * ( texEdge2.y * edge1 - texEdge1.y * edge2)
// bitangent = (1 / det A) * (-texEdge2.x * edge1 + texEdge1.x * edge2)
// normal = cross(tangent, bitangent)
float det = (texEdge1.X * texEdge2.Y) - (texEdge1.Y * texEdge2.X);
if (FastMath.Abs(det) < 0.0001f) // almost equal to zero
{
tangent.X = 1.0f;
tangent.Y = 0.0f;
tangent.Z = 0.0f;
binormal.X = 0.0f;
binormal.Y = 1.0f;
binormal.Z = 0.0f;
}
else
{
det = 1.0f / det;
tangent.X = (texEdge2.Y * edge1.X - texEdge1.Y * edge2.X) * det;
tangent.Y = (texEdge2.Y * edge1.Y - texEdge1.Y * edge2.Y) * det;
tangent.Z = (texEdge2.Y * edge1.Z - texEdge1.Y * edge2.Z) * det;
//tangent.W = 0.0f;
binormal.X = (-texEdge2.X * edge1.X + texEdge1.X * edge2.X) * det;
binormal.Y = (-texEdge2.X * edge1.Y + texEdge1.X * edge2.Y) * det;
binormal.Z = (-texEdge2.X * edge1.Z + texEdge1.X * edge2.Z) * det;
tangent.Normalize();
binormal.Normalize();
}
// Calculate the handedness of the local tangent space.
// The bitangent vector is the cross product between the triangle face
// normal vector and the calculated tangent vector. The resulting bitangent
// vector should be the same as the bitangent vector calculated from the
// set of linear equations above. If they point in different directions
// then we need to invert the cross product calculated bitangent vector.
Vector3 b = Vector3.Cross(v1.Normal, tangent);
float w = Vector3.Dot(b, binormal) < 0.0f ? -1.0f : 1.0f;
binormal = b * w;
}
/// <summary>
/// Crear un TgcMeshBumpMapping en base a un TgcMesh y su normalMap.
/// Solo esta soportado un TgcMehs MeshRenderType = DiffuseMap
/// </summary>
public static TgcMeshBumpMapping fromTgcMesh(TgcMesh mesh, TgcTexture[] normalMaps)
{
if (mesh.RenderType != MeshRenderType.DIFFUSE_MAP)
{
throw new Exception("Solo esta soportado MeshRenderType = DiffuseMap");
}
//Obtener vertexBuffer original
TgcSceneLoader.DiffuseMapVertex[] origVertexBuffer = (TgcSceneLoader.DiffuseMapVertex[])mesh.D3dMesh.LockVertexBuffer(
typeof(TgcSceneLoader.DiffuseMapVertex), LockFlags.ReadOnly, mesh.D3dMesh.NumberVertices);
mesh.D3dMesh.UnlockVertexBuffer();
//Crear nuevo Mesh de DirectX
int triCount = origVertexBuffer.Length / 3;
Mesh d3dMesh = new Mesh(triCount, origVertexBuffer.Length, MeshFlags.Managed, BumpMappingVertexElements, GuiController.Instance.D3dDevice);
//Calcular normales recorriendo los triangulos
Vector3[] normals = new Vector3[origVertexBuffer.Length];
for (int i = 0; i < normals.Length; i++)
{
normals[i] = new Vector3(0, 0, 0);
}
for (int i = 0; i < triCount; i++)
{
//Los 3 vertices del triangulo
TgcSceneLoader.DiffuseMapVertex v1 = origVertexBuffer[i * 3];
TgcSceneLoader.DiffuseMapVertex v2 = origVertexBuffer[i * 3 + 1];
TgcSceneLoader.DiffuseMapVertex v3 = origVertexBuffer[i * 3 + 2];
//Face-normal (left-handend)
Vector3 a = v2.Position - v1.Position;
Vector3 b = v3.Position - v1.Position;
Vector3 n = Vector3.Cross(a, b);
//Acumular normal del vertice segun todas sus Face-normal
normals[i * 3] += n;
normals[i * 3 + 1] += n;
normals[i * 3 + 2] += n;
}
//Normalizar normales
for (int i = 0; i < normals.Length; i++)
{
normals[i] = Vector3.Normalize(normals[i]);
}
//Crear nuevo VertexBuffer
using (VertexBuffer vb = d3dMesh.VertexBuffer)
{
//Iterar sobre triangulos
GraphicsStream data = vb.Lock(0, 0, LockFlags.None);
for (int i = 0; i < triCount; i++)
{
//Vertices originales
TgcSceneLoader.DiffuseMapVertex vOrig1 = origVertexBuffer[i * 3];
TgcSceneLoader.DiffuseMapVertex vOrig2 = origVertexBuffer[i * 3 + 1];
TgcSceneLoader.DiffuseMapVertex vOrig3 = origVertexBuffer[i * 3 + 2];
//Nuevo vertice 1
BumpMappingVertex v1 = new BumpMappingVertex();
v1.Position = vOrig1.Position;
v1.Color = vOrig1.Color;
v1.Tu = vOrig1.Tu;
v1.Tv = vOrig1.Tv;
v1.Normal = normals[i * 3];
//Nuevo vertice 2
BumpMappingVertex v2 = new BumpMappingVertex();
v2.Position = vOrig2.Position;
v2.Color = vOrig2.Color;
v2.Tu = vOrig2.Tu;
v2.Tv = vOrig2.Tv;
v2.Normal = normals[i * 3 + 1];
//Nuevo vertice 3
BumpMappingVertex v3 = new BumpMappingVertex();
v3.Position = vOrig3.Position;
v3.Color = vOrig3.Color;
v3.Tu = vOrig3.Tu;
v3.Tv = vOrig3.Tv;
v3.Normal = normals[i * 3 + 2];
//Calcular tangente y binormal para todo el triangulo y cargarlas en cada vertice
Vector3 tangent;
Vector3 binormal;
TgcMeshBumpMapping.computeTangentBinormal(v1, v2, v3, out tangent, out binormal);
v1.Tangent = tangent;
v1.Binormal = binormal;
v2.Tangent = tangent;
v2.Binormal = binormal;
v3.Tangent = tangent;
v3.Binormal = binormal;
//Cargar VertexBuffer
data.Write(v1);
data.Write(v2);
data.Write(v3);
}
vb.Unlock();
}
//Cargar IndexBuffer en forma plana
using (IndexBuffer ib = d3dMesh.IndexBuffer)
{
short[] indices = new short[origVertexBuffer.Length];
for (int i = 0; i < indices.Length; i++)
{
indices[i] = (short)i;
}
ib.SetData(indices, 0, LockFlags.None);
}
//Clonar texturas y materials
TgcTexture[] diffuseMaps = new TgcTexture[mesh.DiffuseMaps.Length];
Material[] materials = new Material[mesh.Materials.Length];
for (int i = 0; i < mesh.DiffuseMaps.Length; i++)
{
diffuseMaps[i] = mesh.DiffuseMaps[i].clone();
materials[i] = TgcD3dDevice.DEFAULT_MATERIAL;
}
//Cargar attributeBuffer
if (diffuseMaps.Length > 1)
{
int[] origAttributeBuffer = mesh.D3dMesh.LockAttributeBufferArray(LockFlags.None);
int[] newAttributeBuffer = d3dMesh.LockAttributeBufferArray(LockFlags.None);
Array.Copy(origAttributeBuffer, newAttributeBuffer, origAttributeBuffer.Length);
mesh.D3dMesh.UnlockAttributeBuffer();
d3dMesh.UnlockAttributeBuffer(newAttributeBuffer);
}
//Crear mesh de BumpMapping Mesh
TgcMeshBumpMapping bumpMesh = new TgcMeshBumpMapping(d3dMesh, mesh.Name, mesh.RenderType);
bumpMesh.diffuseMaps = diffuseMaps;
bumpMesh.materials = materials;
bumpMesh.normalMaps = normalMaps;
bumpMesh.layer = mesh.Layer;
bumpMesh.alphaBlendEnable = mesh.AlphaBlendEnable;
bumpMesh.UserProperties = mesh.UserProperties;
bumpMesh.boundingBox = mesh.BoundingBox.clone();
bumpMesh.enabled = true;
return(bumpMesh);
}
/// <summary>
/// Crear un TgcMeshBumpMapping en base a un TgcMesh y su normalMap.
/// Solo esta soportado un TgcMehs MeshRenderType = DiffuseMap
/// </summary>
public static TgcMeshBumpMapping fromTgcMesh(TgcMesh mesh, TgcTexture[] normalMaps)
{
if (mesh.RenderType != MeshRenderType.DIFFUSE_MAP)
{
throw new Exception("Solo esta soportado MeshRenderType = DiffuseMap");
}
//Obtener vertexBuffer original
TgcSceneLoader.DiffuseMapVertex[] origVertexBuffer = (TgcSceneLoader.DiffuseMapVertex[])mesh.D3dMesh.LockVertexBuffer(
typeof(TgcSceneLoader.DiffuseMapVertex), LockFlags.ReadOnly, mesh.D3dMesh.NumberVertices);
mesh.D3dMesh.UnlockVertexBuffer();
//Crear nuevo Mesh de DirectX
int triCount = origVertexBuffer.Length / 3;
Mesh d3dMesh = new Mesh(triCount, origVertexBuffer.Length, MeshFlags.Managed, BumpMappingVertexElements, GuiController.Instance.D3dDevice);
//Calcular normales recorriendo los triangulos
Vector3[] normals = new Vector3[origVertexBuffer.Length];
for (int i = 0; i < normals.Length; i++)
{
normals[i] = new Vector3(0, 0, 0);
}
for (int i = 0; i < triCount; i++)
{
//Los 3 vertices del triangulo
TgcSceneLoader.DiffuseMapVertex v1 = origVertexBuffer[i * 3];
TgcSceneLoader.DiffuseMapVertex v2 = origVertexBuffer[i * 3 + 1];
TgcSceneLoader.DiffuseMapVertex v3 = origVertexBuffer[i * 3 + 2];
//Face-normal (left-handend)
Vector3 a = v2.Position - v1.Position;
Vector3 b = v3.Position - v1.Position;
Vector3 n = Vector3.Cross(a, b);
//Acumular normal del vertice segun todas sus Face-normal
normals[i * 3] += n;
normals[i * 3 + 1] += n;
normals[i * 3 + 2] += n;
}
//Normalizar normales
for (int i = 0; i < normals.Length; i++)
{
normals[i] = Vector3.Normalize(normals[i]);
}
//Crear nuevo VertexBuffer
using (VertexBuffer vb = d3dMesh.VertexBuffer)
{
//Iterar sobre triangulos
GraphicsStream data = vb.Lock(0, 0, LockFlags.None);
for (int i = 0; i < triCount; i++)
{
//Vertices originales
TgcSceneLoader.DiffuseMapVertex vOrig1 = origVertexBuffer[i * 3];
TgcSceneLoader.DiffuseMapVertex vOrig2 = origVertexBuffer[i * 3 + 1];
TgcSceneLoader.DiffuseMapVertex vOrig3 = origVertexBuffer[i * 3 + 2];
//Nuevo vertice 1
BumpMappingVertex v1 = new BumpMappingVertex();
v1.Position = vOrig1.Position;
v1.Color = vOrig1.Color;
v1.Tu = vOrig1.Tu;
v1.Tv = vOrig1.Tv;
v1.Normal = normals[i * 3];
//Nuevo vertice 2
BumpMappingVertex v2 = new BumpMappingVertex();
v2.Position = vOrig2.Position;
v2.Color = vOrig2.Color;
v2.Tu = vOrig2.Tu;
v2.Tv = vOrig2.Tv;
v2.Normal = normals[i * 3 + 1];
//Nuevo vertice 3
BumpMappingVertex v3 = new BumpMappingVertex();
v3.Position = vOrig3.Position;
v3.Color = vOrig3.Color;
v3.Tu = vOrig3.Tu;
v3.Tv = vOrig3.Tv;
v3.Normal = normals[i * 3 + 2];
//Calcular tangente y binormal para todo el triangulo y cargarlas en cada vertice
Vector3 tangent;
Vector3 binormal;
TgcMeshBumpMapping.computeTangentBinormal(v1, v2, v3, out tangent, out binormal);
v1.Tangent = tangent;
v1.Binormal = binormal;
v2.Tangent = tangent;
v2.Binormal = binormal;
v3.Tangent = tangent;
v3.Binormal = binormal;
//Cargar VertexBuffer
data.Write(v1);
data.Write(v2);
data.Write(v3);
}
vb.Unlock();
}
//Cargar IndexBuffer en forma plana
using (IndexBuffer ib = d3dMesh.IndexBuffer)
{
short[] indices = new short[origVertexBuffer.Length];
for (int i = 0; i < indices.Length; i++)
{
indices[i] = (short)i;
}
ib.SetData(indices, 0, LockFlags.None);
}
//Clonar texturas y materials
TgcTexture[] diffuseMaps = new TgcTexture[mesh.DiffuseMaps.Length];
Material[] materials = new Material[mesh.Materials.Length];
for (int i = 0; i < mesh.DiffuseMaps.Length; i++)
{
diffuseMaps[i] = mesh.DiffuseMaps[i].clone();
materials[i] = TgcD3dDevice.DEFAULT_MATERIAL;
}
//Cargar attributeBuffer
if (diffuseMaps.Length > 1)
{
int[] origAttributeBuffer = mesh.D3dMesh.LockAttributeBufferArray(LockFlags.None);
int[] newAttributeBuffer = d3dMesh.LockAttributeBufferArray(LockFlags.None);
Array.Copy(origAttributeBuffer, newAttributeBuffer, origAttributeBuffer.Length);
mesh.D3dMesh.UnlockAttributeBuffer();
d3dMesh.UnlockAttributeBuffer(newAttributeBuffer);
}
//Crear mesh de BumpMapping Mesh
TgcMeshBumpMapping bumpMesh = new TgcMeshBumpMapping(d3dMesh, mesh.Name, mesh.RenderType);
bumpMesh.diffuseMaps = diffuseMaps;
bumpMesh.materials = materials;
bumpMesh.normalMaps = normalMaps;
bumpMesh.layer = mesh.Layer;
bumpMesh.alphaBlendEnable = mesh.AlphaBlendEnable;
bumpMesh.UserProperties = mesh.UserProperties;
bumpMesh.boundingBox = mesh.BoundingBox.clone();
bumpMesh.enabled = true;
return bumpMesh;
}
