assimp/code/PostProcessing/JoinVerticesProcess.cpp

439 lines
17 KiB
C++

/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
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*/
/** @file Implementation of the post processing step to join identical vertices
* for all imported meshes
*/
#ifndef ASSIMP_BUILD_NO_JOINVERTICES_PROCESS
#include "JoinVerticesProcess.h"
#include "ProcessHelper.h"
#include <assimp/Vertex.h>
#include <assimp/TinyFormatter.h>
#include <stdio.h>
#include <unordered_set>
using namespace Assimp;
// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
JoinVerticesProcess::JoinVerticesProcess()
{
// nothing to do here
}
// ------------------------------------------------------------------------------------------------
// Destructor, private as well
JoinVerticesProcess::~JoinVerticesProcess()
{
// nothing to do here
}
// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool JoinVerticesProcess::IsActive( unsigned int pFlags) const
{
return (pFlags & aiProcess_JoinIdenticalVertices) != 0;
}
// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void JoinVerticesProcess::Execute( aiScene* pScene)
{
ASSIMP_LOG_DEBUG("JoinVerticesProcess begin");
// get the total number of vertices BEFORE the step is executed
int iNumOldVertices = 0;
if (!DefaultLogger::isNullLogger()) {
for( unsigned int a = 0; a < pScene->mNumMeshes; a++) {
iNumOldVertices += pScene->mMeshes[a]->mNumVertices;
}
}
// execute the step
int iNumVertices = 0;
for( unsigned int a = 0; a < pScene->mNumMeshes; a++)
iNumVertices += ProcessMesh( pScene->mMeshes[a],a);
// if logging is active, print detailed statistics
if (!DefaultLogger::isNullLogger()) {
if (iNumOldVertices == iNumVertices) {
ASSIMP_LOG_DEBUG("JoinVerticesProcess finished ");
} else {
ASSIMP_LOG_INFO_F("JoinVerticesProcess finished | Verts in: ", iNumOldVertices,
" out: ", iNumVertices, " | ~",
((iNumOldVertices - iNumVertices) / (float)iNumOldVertices) * 100.f );
}
}
pScene->mFlags |= AI_SCENE_FLAGS_NON_VERBOSE_FORMAT;
}
namespace {
bool areVerticesEqual(const Vertex &lhs, const Vertex &rhs, bool complex)
{
// A little helper to find locally close vertices faster.
// Try to reuse the lookup table from the last step.
const static float epsilon = 1e-5f;
// Squared because we check against squared length of the vector difference
static const float squareEpsilon = epsilon * epsilon;
// Square compare is useful for animeshes vertices compare
if ((lhs.position - rhs.position).SquareLength() > squareEpsilon) {
return false;
}
// We just test the other attributes even if they're not present in the mesh.
// In this case they're initialized to 0 so the comparison succeeds.
// By this method the non-present attributes are effectively ignored in the comparison.
if ((lhs.normal - rhs.normal).SquareLength() > squareEpsilon) {
return false;
}
if ((lhs.texcoords[0] - rhs.texcoords[0]).SquareLength() > squareEpsilon) {
return false;
}
if ((lhs.tangent - rhs.tangent).SquareLength() > squareEpsilon) {
return false;
}
if ((lhs.bitangent - rhs.bitangent).SquareLength() > squareEpsilon) {
return false;
}
// Usually we won't have vertex colors or multiple UVs, so we can skip from here
// Actually this increases runtime performance slightly, at least if branch
// prediction is on our side.
if (complex) {
for (int i = 0; i < 8; i++) {
if (i > 0 && (lhs.texcoords[i] - rhs.texcoords[i]).SquareLength() > squareEpsilon) {
return false;
}
if (GetColorDifference(lhs.colors[i], rhs.colors[i]) > squareEpsilon) {
return false;
}
}
}
return true;
}
template<class XMesh>
void updateXMeshVertices(XMesh *pMesh, std::vector<Vertex> &uniqueVertices) {
// replace vertex data with the unique data sets
pMesh->mNumVertices = (unsigned int)uniqueVertices.size();
// ----------------------------------------------------------------------------
// NOTE - we're *not* calling Vertex::SortBack() because it would check for
// presence of every single vertex component once PER VERTEX. And our CPU
// dislikes branches, even if they're easily predictable.
// ----------------------------------------------------------------------------
// Position, if present (check made for aiAnimMesh)
if (pMesh->mVertices)
{
delete [] pMesh->mVertices;
pMesh->mVertices = new aiVector3D[pMesh->mNumVertices];
for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
pMesh->mVertices[a] = uniqueVertices[a].position;
}
}
// Normals, if present
if (pMesh->mNormals)
{
delete [] pMesh->mNormals;
pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
for( unsigned int a = 0; a < pMesh->mNumVertices; a++) {
pMesh->mNormals[a] = uniqueVertices[a].normal;
}
}
// Tangents, if present
if (pMesh->mTangents)
{
delete [] pMesh->mTangents;
pMesh->mTangents = new aiVector3D[pMesh->mNumVertices];
for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
pMesh->mTangents[a] = uniqueVertices[a].tangent;
}
}
// Bitangents as well
if (pMesh->mBitangents)
{
delete [] pMesh->mBitangents;
pMesh->mBitangents = new aiVector3D[pMesh->mNumVertices];
for (unsigned int a = 0; a < pMesh->mNumVertices; a++) {
pMesh->mBitangents[a] = uniqueVertices[a].bitangent;
}
}
// Vertex colors
for (unsigned int a = 0; pMesh->HasVertexColors(a); a++)
{
delete [] pMesh->mColors[a];
pMesh->mColors[a] = new aiColor4D[pMesh->mNumVertices];
for( unsigned int b = 0; b < pMesh->mNumVertices; b++) {
pMesh->mColors[a][b] = uniqueVertices[b].colors[a];
}
}
// Texture coords
for (unsigned int a = 0; pMesh->HasTextureCoords(a); a++)
{
delete [] pMesh->mTextureCoords[a];
pMesh->mTextureCoords[a] = new aiVector3D[pMesh->mNumVertices];
for (unsigned int b = 0; b < pMesh->mNumVertices; b++) {
pMesh->mTextureCoords[a][b] = uniqueVertices[b].texcoords[a];
}
}
}
} // namespace
// ------------------------------------------------------------------------------------------------
// Unites identical vertices in the given mesh
int JoinVerticesProcess::ProcessMesh( aiMesh* pMesh, unsigned int meshIndex)
{
static_assert( AI_MAX_NUMBER_OF_COLOR_SETS == 8, "AI_MAX_NUMBER_OF_COLOR_SETS == 8");
static_assert( AI_MAX_NUMBER_OF_TEXTURECOORDS == 8, "AI_MAX_NUMBER_OF_TEXTURECOORDS == 8");
// Return early if we don't have any positions
if (!pMesh->HasPositions() || !pMesh->HasFaces()) {
return 0;
}
// We should care only about used vertices, not all of them
// (this can happen due to original file vertices buffer being used by
// multiple meshes)
std::unordered_set<unsigned int> usedVertexIndices;
usedVertexIndices.reserve(pMesh->mNumVertices);
for( unsigned int a = 0; a < pMesh->mNumFaces; a++)
{
aiFace& face = pMesh->mFaces[a];
for( unsigned int b = 0; b < face.mNumIndices; b++) {
usedVertexIndices.insert(face.mIndices[b]);
}
}
// We'll never have more vertices afterwards.
std::vector<Vertex> uniqueVertices;
uniqueVertices.reserve( pMesh->mNumVertices);
// For each vertex the index of the vertex it was replaced by.
// Since the maximal number of vertices is 2^31-1, the most significand bit can be used to mark
// whether a new vertex was created for the index (true) or if it was replaced by an existing
// unique vertex (false). This saves an additional std::vector<bool> and greatly enhances
// branching performance.
static_assert(AI_MAX_VERTICES == 0x7fffffff, "AI_MAX_VERTICES == 0x7fffffff");
std::vector<unsigned int> replaceIndex( pMesh->mNumVertices, 0xffffffff);
// float posEpsilonSqr;
SpatialSort* vertexFinder = NULL;
SpatialSort _vertexFinder;
typedef std::pair<SpatialSort,float> SpatPair;
if (shared) {
std::vector<SpatPair >* avf;
shared->GetProperty(AI_SPP_SPATIAL_SORT,avf);
if (avf) {
SpatPair& blubb = (*avf)[meshIndex];
vertexFinder = &blubb.first;
// posEpsilonSqr = blubb.second;
}
}
if (!vertexFinder) {
// bad, need to compute it.
_vertexFinder.Fill(pMesh->mVertices, pMesh->mNumVertices, sizeof( aiVector3D));
vertexFinder = &_vertexFinder;
// posEpsilonSqr = ComputePositionEpsilon(pMesh);
}
// Again, better waste some bytes than a realloc ...
std::vector<unsigned int> verticesFound;
verticesFound.reserve(10);
// Run an optimized code path if we don't have multiple UVs or vertex colors.
// This should yield false in more than 99% of all imports ...
const bool complex = ( pMesh->GetNumColorChannels() > 0 || pMesh->GetNumUVChannels() > 1);
const bool hasAnimMeshes = pMesh->mNumAnimMeshes > 0;
// We'll never have more vertices afterwards.
std::vector<std::vector<Vertex>> uniqueAnimatedVertices;
if (hasAnimMeshes) {
uniqueAnimatedVertices.resize(pMesh->mNumAnimMeshes);
for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
uniqueAnimatedVertices[animMeshIndex].reserve(pMesh->mNumVertices);
}
}
// Now check each vertex if it brings something new to the table
for( unsigned int a = 0; a < pMesh->mNumVertices; a++) {
if (usedVertexIndices.find(a) == usedVertexIndices.end()) {
continue;
}
// collect the vertex data
Vertex v(pMesh,a);
// collect all vertices that are close enough to the given position
vertexFinder->FindIdenticalPositions( v.position, verticesFound);
unsigned int matchIndex = 0xffffffff;
// check all unique vertices close to the position if this vertex is already present among them
for( unsigned int b = 0; b < verticesFound.size(); b++) {
const unsigned int vidx = verticesFound[b];
const unsigned int uidx = replaceIndex[ vidx];
if( uidx & 0x80000000)
continue;
const Vertex& uv = uniqueVertices[ uidx];
if (!areVerticesEqual(v, uv, complex)) {
continue;
}
if (hasAnimMeshes) {
// If given vertex is animated, then it has to be preserver 1 to 1 (base mesh and animated mesh require same topology)
// NOTE: not doing this totaly breaks anim meshes as they don't have their own faces (they use pMesh->mFaces)
bool breaksAnimMesh = false;
for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
const Vertex& animatedUV = uniqueAnimatedVertices[animMeshIndex][ uidx];
Vertex aniMeshVertex(pMesh->mAnimMeshes[animMeshIndex], a);
if (!areVerticesEqual(aniMeshVertex, animatedUV, complex)) {
breaksAnimMesh = true;
break;
}
}
if (breaksAnimMesh) {
continue;
}
}
// we're still here -> this vertex perfectly matches our given vertex
matchIndex = uidx;
break;
}
// found a replacement vertex among the uniques?
if( matchIndex != 0xffffffff)
{
// store where to found the matching unique vertex
replaceIndex[a] = matchIndex | 0x80000000;
}
else
{
// no unique vertex matches it up to now -> so add it
replaceIndex[a] = (unsigned int)uniqueVertices.size();
uniqueVertices.push_back( v);
if (hasAnimMeshes) {
for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
Vertex aniMeshVertex(pMesh->mAnimMeshes[animMeshIndex], a);
uniqueAnimatedVertices[animMeshIndex].push_back(aniMeshVertex);
}
}
}
}
if (!DefaultLogger::isNullLogger() && DefaultLogger::get()->getLogSeverity() == Logger::VERBOSE) {
ASSIMP_LOG_VERBOSE_DEBUG_F(
"Mesh ",meshIndex,
" (",
(pMesh->mName.length ? pMesh->mName.data : "unnamed"),
") | Verts in: ",pMesh->mNumVertices,
" out: ",
uniqueVertices.size(),
" | ~",
((pMesh->mNumVertices - uniqueVertices.size()) / (float)pMesh->mNumVertices) * 100.f,
"%"
);
}
updateXMeshVertices(pMesh, uniqueVertices);
if (hasAnimMeshes) {
for (unsigned int animMeshIndex = 0; animMeshIndex < pMesh->mNumAnimMeshes; animMeshIndex++) {
updateXMeshVertices(pMesh->mAnimMeshes[animMeshIndex], uniqueAnimatedVertices[animMeshIndex]);
}
}
// adjust the indices in all faces
for( unsigned int a = 0; a < pMesh->mNumFaces; a++)
{
aiFace& face = pMesh->mFaces[a];
for( unsigned int b = 0; b < face.mNumIndices; b++) {
face.mIndices[b] = replaceIndex[face.mIndices[b]] & ~0x80000000;
}
}
// adjust bone vertex weights.
for( int a = 0; a < (int)pMesh->mNumBones; a++) {
aiBone* bone = pMesh->mBones[a];
std::vector<aiVertexWeight> newWeights;
newWeights.reserve( bone->mNumWeights);
if ( NULL != bone->mWeights ) {
for ( unsigned int b = 0; b < bone->mNumWeights; b++ ) {
const aiVertexWeight& ow = bone->mWeights[ b ];
// if the vertex is a unique one, translate it
if ( !( replaceIndex[ ow.mVertexId ] & 0x80000000 ) ) {
aiVertexWeight nw;
nw.mVertexId = replaceIndex[ ow.mVertexId ];
nw.mWeight = ow.mWeight;
newWeights.push_back( nw );
}
}
} else {
ASSIMP_LOG_ERROR( "X-Export: aiBone shall contain weights, but pointer to them is NULL." );
}
if (newWeights.size() > 0) {
// kill the old and replace them with the translated weights
delete [] bone->mWeights;
bone->mNumWeights = (unsigned int)newWeights.size();
bone->mWeights = new aiVertexWeight[bone->mNumWeights];
memcpy( bone->mWeights, &newWeights[0], bone->mNumWeights * sizeof( aiVertexWeight));
}
}
return pMesh->mNumVertices;
}
#endif // !! ASSIMP_BUILD_NO_JOINVERTICES_PROCESS