所以我需要编辑这个问题。如其中一条评论所述，我更改为使用缓冲区的渲染方法。但是，几何图形未正确绘制。如果我使用相同的缓冲区并手动绘制顶点，它看起来还不错（虽然没有纹理，但有些东西搞砸了）。我也尝试用顶点信息构建一个缓冲区，但这根本没有帮助。
void ModelHandler::DrawModels(){
//go through each of the models
for(int i=0;i<Models3D.size();i++){
//glEnableClientState(GL_VERTEX_ARRAY);
//glVertexPointer(3, GL_FLOAT, 0, Models3D[i]->object.m_pVertice);
//now draw all the material groups with their vertices for the model
for(int j=0;j<Models3D[i]->object.mtlGroups.size();j++){
//Drawing the vertices manually from the buffer object seems to work
/*
for(int lj=0;lj<Models3D[i]->object.mtlGroups[j]->m_vecgroupVerticeIndex.size();lj++){
int mtlIndex2 = Models3D[i]->object.FindMaterial(Models3D[i]->object.mtlGroups[j]->mtlName);
bool tOn = false;
//check if there was a texture for this material
if(Models3D[i]->object.materials[mtlIndex2]->texturePresent){
glEnable(GL_TEXTURE_2D);
//glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glBindTexture(GL_TEXTURE_2D, Models3D[i]->object.materials[mtlIndex2]->textureIDDiffuse);
tOn = true;
}
if(tOn){
glBegin (GL_QUADS);
glTexCoord2f (0.0, 0.0);
glVertex3f (0.0+5, 0.0, -2.0f);
glTexCoord2f (1.0, 0.0);
glVertex3f (1.4f+5, 0.0, -2.0f);
glTexCoord2f (1.0, 1.0);
glVertex3f (1.4f+5, -1.0, -2.0f);
glTexCoord2f (0.0, 1.0);
glVertex3f (0.0f+5, -1.0, -2.0f);
glEnd ();
}
glBegin(GL_TRIANGLES);
glColor3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3].colour[0],Models3D[i]->object.mtlGroups[j]->VBO[lj*3].colour[1],Models3D[i]->object.mtlGroups[j]->VBO[lj*3].colour[2]);
if(tOn){
glTexCoord2f (Models3D[i]->object.mtlGroups[j]->VBO[lj*3].tex[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3].tex[1]);
}
glVertex3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3].location[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3].location[1], Models3D[i]->object.mtlGroups[j]->VBO[lj*3].location[2]);
glColor3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].colour[0],Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].colour[1],Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].colour[2]);
if(tOn){
glTexCoord2f (Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].tex[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].tex[1]);
}
glVertex3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].location[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].location[1], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+1].location[2]);
glColor3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].colour[0],Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].colour[1],Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].colour[2]);
if(tOn){
glTexCoord2f (Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].tex[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].tex[1]);
}
glVertex3f(Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].location[0], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].location[1], Models3D[i]->object.mtlGroups[j]->VBO[lj*3+2].location[2]);
glEnd();
}
glDisable(GL_TEXTURE_2D);
*/
//####
glBindBuffer(GL_ARRAY_BUFFER, Models3D[i]->object.mtlGroups[j]->vboID);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, Models3D[i]->object.mtlGroups[j]->indexvboID);
/*
//this could also be used BUT if glDrawElements uses the indices (m_pgroupVerticeIndex), we will need to give the array with all the
//vertices to glVertexPointer. That array would be m_pVertice
//glVertexPointer(3, GL_FLOAT, 5, Models3D[i]->object.mtlGroups[j]->buffer);
*/
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);
//Get the material that belongs to this mtlGroup
int mtlIndex = Models3D[i]->object.FindMaterial(Models3D[i]->object.mtlGroups[j]->mtlName);
//check if there was a texture for this material
if(Models3D[i]->object.materials[mtlIndex]->texturePresent){
glEnable(GL_TEXTURE_2D);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glBindTexture(GL_TEXTURE_2D, Models3D[i]->object.materials[mtlIndex]->textureIDDiffuse);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(12));
//glTexCoordPointer(2, GL_FLOAT, 5, Models3D[i]->object.mtlGroups[j]->buffer);
//glTexCoordPointer(2, GL_FLOAT, 0, Models3D[i]->object.m_pTexture);
}
// Resetup our pointers. This doesn't reinitialise any data, only how we walk through it
glNormalPointer(GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(20));
glColorPointer(3, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(32));
glVertexPointer(3, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(0));
glDrawElements(GL_TRIANGLES, Models3D[i]->object.mtlGroups[j]->m_vecgroupVerticeIndex.size()*3, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
//glDrawElements(GL_TRIANGLES, Models3D[i]->object.mtlGroups[j]->m_vecgroupVerticeIndex.size()*3, GL_UNSIGNED_INT, Models3D[i]->object.mtlGroups[j]->m_pgroupVerticeIndex);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
glDisable(GL_TEXTURE_2D);
}
}
}
我的缓冲区包含顶点（顶点结构数组）：
struct Vertex {
GLfloat location[3];
GLfloat tex[2];
GLfloat normal[3];
GLfloat colour[3];
GLubyte padding[20]; //apparently to get 64 bytes -> improved performance
};
以下是我为每种材料初始化/生成缓冲区的方法：
//This function was implemented based on the tutorial shown at
//http://sdickinson.com/wordpress/?p=122
void CObjLoader::GenerateVBO(){
for(int mj=0;mj<mtlGroups.size();mj++){
glGenBuffers(1, &mtlGroups[mj]->vboID);
//printf("bufferID: %d", mtlGroups[mj]->vboID);
glBindBuffer(GL_ARRAY_BUFFER, mtlGroups[mj]->vboID); // Bind the buffer (vertex array data)
// Allocate space. We could pass the mesh in here (where the NULL is), but it's actually faster to do it as a
// seperate step. We also define it as GL_STATIC_DRAW which means we set the data once, and never
// update it. This is not a strict rule code wise, but gives hints to the driver as to where to store the data
glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex) * mtlGroups[mj]->m_vecgroupVerticeIndex.size()*3, NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(Vertex) * mtlGroups[mj]->m_vecgroupVerticeIndex.size()*3, mtlGroups[mj]->VBO); // Actually upload the data
// Set the pointers to our data. Except for the normal value (which always has a size of 3), we must pass
// the size of the individual component. ie. A vertex has 3 points (x, y, z), texture coordinates have 2 (u, v) etc.
// Basically the arguments are (ignore the first one for the normal pointer), Size (many components to
// read), Type (what data type is it), Stride (how far to move forward - in bytes - per vertex) and Offset
// (where in the buffer to start reading the data - in bytes)
// Make sure you put glVertexPointer at the end as there is a lot of work that goes on behind the scenes
// with it, and if it's set at the start, it has to do all that work for each gl*Pointer call, rather than once at
// the end.
glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(12));
glNormalPointer(GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(20));
glColorPointer(3, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(32));
glVertexPointer(3, GL_FLOAT, sizeof(Vertex), BUFFER_OFFSET(0));
// When we get here, all the vertex data is effectively on the card
// Our Index Buffer, same as above, the variable needs to be accessible wherever we draw
glGenBuffers(1, &mtlGroups[mj]->indexvboID); // Generate buffer
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mtlGroups[mj]->indexvboID); // Bind the element array buffer
// Upload the index array, this can be done the same way as above (with NULL as the data, then a
// glBufferSubData call, but doing it all at once for convenience)
glBufferData(GL_ELEMENT_ARRAY_BUFFER, mtlGroups[mj]->m_vecgroupVerticeIndex.size()*3*sizeof(GLubyte), mtlGroups[mj]->index, GL_STATIC_DRAW);
}
}
为简单起见，我的索引数组如下所示：0,1,2,3,4,5,...。这意味着我的缓冲区包含一些顶点两次。因此 VBO 和索引具有相同的长度。
也许我在初始化时搞砸了？