assimp/code/3DSGenNormals.cpp

134 lines
3.9 KiB
C++

/** @file Implementation of the 3ds importer class */
#include "3DSLoader.h"
#include "MaterialSystem.h"
#include <algorithm>
#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"
#include "3DSSpatialSort.h"
using namespace Assimp;
// ------------------------------------------------------------------------------------------------
void Dot3DSImporter::GenNormals(Dot3DS::Mesh* sMesh)
{
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// First generate face normals
sMesh->mNormals.resize(sMesh->mPositions.size(),aiVector3D());
for( unsigned int a = 0; a < sMesh->mFaces.size(); a++)
{
const Dot3DS::Face& face = sMesh->mFaces[a];
// assume it is a triangle
aiVector3D* pV1 = &sMesh->mPositions[face.i1];
aiVector3D* pV2 = &sMesh->mPositions[face.i2];
aiVector3D* pV3 = &sMesh->mPositions[face.i3];
aiVector3D pDelta1 = *pV2 - *pV1;
aiVector3D pDelta2 = *pV3 - *pV1;
aiVector3D vNor = pDelta1 ^ pDelta2;
//float fLength = vNor.Length();
//if (0.0f != fLength)vNor /= fLength;
sMesh->mNormals[face.i1] = vNor;
sMesh->mNormals[face.i2] = vNor;
sMesh->mNormals[face.i3] = vNor;
}
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// calculate the position bounds so we have a reliable epsilon to
// check position differences against
// @Schrompf: This is the 6th time this snippet is repeated!
aiVector3D minVec( 1e10f, 1e10f, 1e10f), maxVec( -1e10f, -1e10f, -1e10f);
for( unsigned int a = 0; a < sMesh->mPositions.size(); a++)
{
minVec.x = std::min( minVec.x, sMesh->mPositions[a].x);
minVec.y = std::min( minVec.y, sMesh->mPositions[a].y);
minVec.z = std::min( minVec.z, sMesh->mPositions[a].z);
maxVec.x = std::max( maxVec.x, sMesh->mPositions[a].x);
maxVec.y = std::max( maxVec.y, sMesh->mPositions[a].y);
maxVec.z = std::max( maxVec.z, sMesh->mPositions[a].z);
}
const float posEpsilon = (maxVec - minVec).Length() * 1e-5f;
std::vector<aiVector3D> avNormals;
avNormals.resize(sMesh->mNormals.size());
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// now generate the spatial sort tree
D3DSSpatialSorter sSort(sMesh);
for( std::vector<Dot3DS::Face>::iterator
i = sMesh->mFaces.begin();
i != sMesh->mFaces.end();++i)
{
std::vector<unsigned int> poResult;
// need to repeat the code for all three vertices of the triangle
// vertex 1
sSort.FindPositions(sMesh->mPositions[(*i).i1],(*i).iSmoothGroup,
posEpsilon,poResult);
aiVector3D vNormals;
float fDiv = 0.0f;
for (std::vector<unsigned int>::const_iterator
a = poResult.begin();
a != poResult.end();++a)
{
vNormals += sMesh->mNormals[(*a)];
fDiv += 1.0f;
}
vNormals.x /= fDiv;
vNormals.y /= fDiv;
vNormals.z /= fDiv;
vNormals.Normalize();
avNormals[(*i).i1] = vNormals;
poResult.clear();
// vertex 2
sSort.FindPositions(sMesh->mPositions[(*i).i2],(*i).iSmoothGroup,
posEpsilon,poResult);
vNormals = aiVector3D();
fDiv = 0.0f;
for (std::vector<unsigned int>::const_iterator
a = poResult.begin();
a != poResult.end();++a)
{
vNormals += sMesh->mNormals[(*a)];
fDiv += 1.0f;
}
vNormals.x /= fDiv;
vNormals.y /= fDiv;
vNormals.z /= fDiv;
vNormals.Normalize();
avNormals[(*i).i2] = vNormals;
poResult.clear();
// vertex 3
sSort.FindPositions(sMesh->mPositions[(*i).i3],(*i).iSmoothGroup,
posEpsilon ,poResult);
vNormals = aiVector3D();
fDiv = 0.0f;
for (std::vector<unsigned int>::const_iterator
a = poResult.begin();
a != poResult.end();++a)
{
vNormals += sMesh->mNormals[(*a)];
fDiv += 1.0f;
}
vNormals.x /= fDiv;
vNormals.y /= fDiv;
vNormals.z /= fDiv;
vNormals.Normalize();
avNormals[(*i).i3] = vNormals;
}
sMesh->mNormals = avNormals;
return;
}