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Add support for tangents in glTF2.0 import 

Closes #1562
pull/1596/head
awefers 2017-11-27 13:45:15 -05:00 committed by Daniel Hritzkiv
parent 0ce3641deb
commit 0031165789
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GPG Key ID: D1D19875679D5CBF
3 changed files with 30 additions and 3 deletions
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2
code/glTF2Asset.h
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@ -775,7 +775,7 @@ namespace glTF2
PrimitiveMode mode;
struct Attributes {
AccessorList position, normal, texcoord, color, joint, jointmatrix, weight;
AccessorList position, normal, tangent, texcoord, color, joint, jointmatrix, weight;
} attributes;
Ref<Accessor> indices;

5
code/glTF2Asset.inl
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@ -867,6 +867,9 @@ namespace {
else if ((pos = Compare(attr, "NORMAL"))) {
v = &(p.attributes.normal);
}
else if ((pos = Compare(attr, "TANGENT"))) {
v = &(p.attributes.tangent);
}
else if ((pos = Compare(attr, "TEXCOORD"))) {
v = &(p.attributes.texcoord);
}
@ -906,7 +909,7 @@ inline void Mesh::Read(Value& pJSON_Object, Asset& pAsset_Root)
for (Value::MemberIterator it = attrs->MemberBegin(); it != attrs->MemberEnd(); ++it) {
if (!it->value.IsUint()) continue;
const char* attr = it->name.GetString();
// Valid attribute semantics include POSITION, NORMAL, TEXCOORD, COLOR, JOINT, JOINTMATRIX,
// Valid attribute semantics include POSITION, NORMAL, TANGENT, TEXCOORD, COLOR, JOINT, JOINTMATRIX,
// and WEIGHT.Attribute semantics can be of the form[semantic]_[set_index], e.g., TEXCOORD_0, TEXCOORD_1, etc.
int undPos = 0;

26
code/glTF2Importer.cpp
View File

@ -362,7 +362,31 @@ void glTF2Importer::ImportMeshes(glTF2::Asset& r)
attr.position[0]->ExtractData(aim->mVertices);
}
if (attr.normal.size() > 0 && attr.normal[0]) attr.normal[0]->ExtractData(aim->mNormals);
if (attr.normal.size() > 0 && attr.normal[0]) {
attr.normal[0]->ExtractData(aim->mNormals);
// only extract tangents if normals are present
if (attr.tangent.size() > 0 && attr.tangent[0]) {
// generate bitangents from normals and tangents according to spec
struct Tangent
{
aiVector3D xyz;
ai_real w;
} *tangents = nullptr;
attr.tangent[0]->ExtractData(tangents);
aim->mTangents = new aiVector3D[aim->mNumVertices];
aim->mBitangents = new aiVector3D[aim->mNumVertices];
for (unsigned int i = 0; i < aim->mNumVertices; ++i) {
aim->mTangents[i] = tangents[i].xyz;
aim->mBitangents[i] = (aim->mNormals[i] ^ tangents[i].xyz) * tangents[i].w;
}
delete tangents;
}
}
for (size_t tc = 0; tc < attr.texcoord.size() && tc < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++tc) {
attr.texcoord[tc]->ExtractData(aim->mTextureCoords[tc]);