最近一直在试图把魔兽3的mdx文件转为Ogre Mesh，学习一下基础的3D编程。Ogre Mesh的导出在很久之前也曾试图做过，并且还把WOW的m2模型以及WMO模型导入到了Max中，但是只做到了骨架的导入，动画数据始终出不来，于是放弃。
这次依然是碰到这里的问题，导出静态的Mesh很快就完成，包括模型与材质，代码也比较简单。
// 模型数据
bool ModelLoaderMdx::loadGeosets(Ogre::MeshPtr model, MdxDataStreamPtr dataStream, int size)
{
unsigned int index = 0;
while(size > 0)
{
int geosetSize = dataStream->read<int>();
size -= geosetSize;
Ogre::String meshName = m_modelName + Ogre::String("_sub_") + Ogre::StringConverter::toString(index++);
Ogre::SubMesh* subMesh = model->createSubMesh(meshName);
// 硬件缓冲编号
// 分别为顶点坐标 法线 贴图坐标
#define HARDWARE_BUFFER_SOURCE_VERTEX 0
#define HARDWARE_BUFFER_SOURCE_NORMAL 1
#define HARDWARE_BUFFER_SOURCE_TEXPOS 2
//
// 顶点数据
//
if(!expectTag(dataStream, 'VRTX'))
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "Expect VRTX data for geoset",
"ModelLoaderMdx::loadGeosets");
}
unsigned int vertexCount = dataStream->read<unsigned int>();
// 不使用共享顶点数据
// 每个SubMesh都创建自己的VertexData
subMesh->useSharedVertices = false;
subMesh->vertexData = OGRE_NEW Ogre::VertexData();
subMesh->vertexData->vertexStart = 0;
subMesh->vertexData->vertexCount = vertexCount;
subMesh->vertexData->vertexDeclaration->addElement(
HARDWARE_BUFFER_SOURCE_VERTEX, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
size_t vertexSize = sizeof(float) * 3;
assert(subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_VERTEX) == vertexSize);
if (subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_VERTEX) != vertexSize)
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "VertexSize error",
"ModelLoaderMdx::loadGeoset");
}
Ogre::HardwareVertexBufferSharedPtr vertexBuffer;
vertexBuffer = Ogre::HardwareBufferManager::getSingleton().createVertexBuffer(
vertexSize,
vertexCount,
Ogre::HardwareBuffer::HBU_STATIC_WRITE_ONLY);
void* vertexBufferData = vertexBuffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);
unsigned int vertexBufferDataPos = 0;
for (unsigned int i = 0; i < vertexCount; ++i)
{
Ogre::Vector3 data(
dataStream->read<float>(),
dataStream->read<float>(),
dataStream->read<float>()
);
transformCoord(data);
memcpy((char*)vertexBufferData + vertexBufferDataPos, &data, sizeof(Ogre::Vector3));
vertexBufferDataPos += sizeof(Ogre::Vector3);
}
vertexBuffer->unlock();
subMesh->vertexData->vertexBufferBinding->setBinding(HARDWARE_BUFFER_SOURCE_VERTEX, vertexBuffer);
//
// 法线数据
//
if(!expectTag(dataStream, 'NRMS'))
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "Expect NRMS data for material",
"ModelLoaderMdx::loadGeosets");
}
unsigned int normalCount = dataStream->read<unsigned int>();
if(normalCount != vertexCount)
{
std::stringstream stream;
stream << "Normal count mismatch, " << normalCount << " normals for " << vertexCount << " vertices)!";
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, stream.str(),
"ModelLoaderMdx::loadGeoset");
}
subMesh->vertexData->vertexDeclaration->addElement(
HARDWARE_BUFFER_SOURCE_NORMAL, 0, Ogre::VET_FLOAT3, Ogre::VES_NORMAL);
size_t normalSize = sizeof(float) * 3;
assert(subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_NORMAL) == normalSize);
if (subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_NORMAL) != normalSize)
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "NormalSize error",
"ModelLoaderMdx::loadGeoset");
}
Ogre::HardwareVertexBufferSharedPtr normalBuffer;
normalBuffer = Ogre::HardwareBufferManager::getSingleton().createVertexBuffer(
normalSize,
normalCount,
Ogre::HardwareBuffer::HBU_STATIC_WRITE_ONLY);
void* normalBufferData = normalBuffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);
unsigned int normalBufferDataPos = 0;
for (unsigned int i = 0; i < normalCount; ++i)
{
Ogre::Vector3 data(
dataStream->read<float>(),
dataStream->read<float>(),
dataStream->read<float>()
);
transformCoord(data);
memcpy((char*)normalBufferData + normalBufferDataPos, &data, sizeof(Ogre::Vector3));
normalBufferDataPos += sizeof(Ogre::Vector3);
}
normalBuffer->unlock();
subMesh->vertexData->vertexBufferBinding->setBinding(HARDWARE_BUFFER_SOURCE_NORMAL, normalBuffer);
………… //
// 顶点索引
//
if(!expectTag(dataStream, 'PVTX'))
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "Expect PVTX data for geoset",
"ModelLoaderMdx::loadGeosets");
}
unsigned int indexCount = dataStream->read<unsigned int>();
assert(totalIndexCount == indexCount);
if (totalIndexCount != indexCount)
{
std::stringstream stream;
stream << "indexCount is " << indexCount << ", but totalIndexCount for all faces is " << totalIndexCount;
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, stream.str(),
"ModelLoaderMdx::loadGeoset");
}
subMesh->indexData->indexStart = 0;
subMesh->indexData->indexCount = indexCount;
Ogre::HardwareIndexBufferSharedPtr indexBuffer;
indexBuffer = Ogre::HardwareBufferManager::getSingleton().createIndexBuffer(
Ogre::HardwareIndexBuffer::IT_16BIT,
indexCount,
Ogre::HardwareBuffer::HBU_STATIC_WRITE_ONLY);
void* indexBufferData = indexBuffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);
dataStream->read(indexBufferData, indexCount * sizeof(unsigned short));
// 三角形反转, 将原来的反面朝外
unsigned short* tmpData = (unsigned short*)indexBufferData;
for (unsigned int i = 0; i < indexCount; i += 3)
{
unsigned short tmp = tmpData[i + 1];
tmpData[i + 1] = tmpData[i + 2];
tmpData[i + 2] = tmp;
}
indexBuffer->unlock();
subMesh->indexData->indexBuffer = indexBuffer;
subMesh->operationType = Ogre::RenderOperation::OT_TRIANGLE_LIST;
…………
// 材质ID
unsigned int materialID = dataStream->read<unsigned int>();
Ogre::String materialName = m_modelName + Ogre::String("_") + boost::lexical_cast<Ogre::String>(materialID);
subMesh->setMaterialName(materialName);
…………
//
// 贴图坐标
//
if(!expectTag(dataStream, 'UVBS'))
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "Expect UVBS data for geoset",
"ModelLoaderMdx::loadGeosets");
}
unsigned int texturePositionCount = dataStream->read<unsigned int>();
if(texturePositionCount != vertexCount)
{
std::stringstream stream;
stream << "Texture position count mismatch, " << texturePositionCount << " texture positions for " << vertexCount << " vertices)!";
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, stream.str(),
"ModelLoaderMdx::loadGeoset");
}
// TextureCoord Data
subMesh->vertexData->vertexDeclaration->addElement(
HARDWARE_BUFFER_SOURCE_TEXPOS, 0, Ogre::VET_FLOAT2, Ogre::VES_TEXTURE_COORDINATES);
size_t texPosSize = sizeof(float) * 2;
assert(subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_TEXPOS) == texPosSize);
if (subMesh->vertexData->vertexDeclaration->getVertexSize(HARDWARE_BUFFER_SOURCE_TEXPOS) != texPosSize)
{
OGRE_EXCEPT(Ogre::Exception::ERR_INTERNAL_ERROR, "TexturePositionSize error",
"ModelLoaderMdx::loadGeoset");
}
Ogre::HardwareVertexBufferSharedPtr texPosBuffer;
texPosBuffer = Ogre::HardwareBufferManager::getSingleton().createVertexBuffer(
texPosSize,
texturePositionCount,
Ogre::HardwareBuffer::HBU_STATIC_WRITE_ONLY);
void* texPosBufferData = texPosBuffer->lock(Ogre::HardwareBuffer::HBL_DISCARD);
dataStream->read(texPosBufferData, texPosSize * texturePositionCount);
texPosBuffer->unlock();
subMesh->vertexData->vertexBufferBinding->setBinding(HARDWARE_BUFFER_SOURCE_TEXPOS, texPosBuffer);
}
return true;
}
但是到了动画数据这里问题又出来了，而且mdx模型与m2模型还有些差别，mdx模型中没有骨骼数据，只有max中最简单的三种变换数据，Ogre中只有MorphAnimation能够实现此种动画。
Ogre的MorphAnimation的第一个KeyFrame必须带有完整的顶点信息，而mdx模型中旋转、缩放与位移是分开的，也就是一个KeyFrame上可能只有一种变换，或者多种。而实际上在max中制作动画的时候这三种变换也是独立开的，Ogre的论坛上找到一篇讨论有人提到了这个问题，可惜制作者的回复是MorphAnimation只实现到这样……
也确实，现在除了一些小物件的动画外，主角，怪物的动画都用skeleton了，也许MorphAnimation就快退出历史的舞台，在Ogre中看不到了，也不能指望会有什么改进。
继续实现之，那就只能在有KeyFrame的地方把三种变换都计算一次，然后取得最终变换后的位置数据，也就是做人工的动画帧采样。在War3EditorSource的基础上做了些修改，终于，一帧帧的动画计算出来了。
不过问题依然还有很多，比如mdx模型，尤其是怪物和角色模型中大量用到了ReplacableTexture，这些需要通过读配置文件来获取可用的贴图，另外模型上附带的粒子特效、纹理动画等都还没有导出，看看这个没有贴图的攻击中的蝎子，前面的路仍然很远。
