所以，在过去的一个半星期里，我一直在研究这个 .OBJ/.MTL 网格解析器。在这段时间内，我一直在追踪/修复很多错误，清理代码，记录它等等。
问题是，随着我修复的每个错误，仍然会出现这个问题，因为一张图片值得一千字......
使用 GL_LINE_LOOP
（注意：右边的金字塔从球体向外倾斜是这里的问题）
使用 GL_TRIANGLES
更有趣的是，当在场景中漂浮时，这个“坏”的顶点数据似乎会随着相机移动……除了它会缩放并粘在网格之外。
奇怪的是，虽然我确定问题与内存有关，但我一直在检查与解析算法是否正常工作相矛盾的问题。经过一些单元测试，它似乎工作正常。
所以，我认为这可能是 Linux nVidia 驱动程序的问题。我将驱动程序更新到下一个版本，重新启动，仍然没有骰子。
经过一番深思熟虑，我一直试图在以下代码中找到错误。
//! every 3 vertices should represent a triangle, therefore we'll want to
//! use the indices to grab their corresponding vertices. Since the cross product
//! of two sides of every triangle (where one side = Vn - Vm, 'n' and 'm' being on the range of 1..3),
//! we first grab the three vertices, and then compute the normal using the their differences.
const uInt32 length = mesh->vertices.size();
//! declare a pointer to the vector so we can perform simple
//! memory copies to get the indices for each triangle within the
//! iteration.
GLuint* const pIndexBuf = &mesh->indices[ 0 ];
for ( uInt32 i = 0; i < length; i += 3 )
{
GLuint thisTriIndices[ 3 ];
memcpy( thisTriIndices, pIndexBuf + i, sizeof( GLuint ) * 3 );
vec3 vertexOne = vec3( mesh->vertices[ thisTriIndices[ 0 ] ] );
vec3 vertexTwo = vec3( mesh->vertices[ thisTriIndices[ 1 ] ] );
vec3 vertexThree = vec3( mesh->vertices[ thisTriIndices[ 2 ] ] );
vec3 sideOne = vertexTwo - vertexOne;
vec3 sideTwo = vertexThree - vertexOne;
vec3 surfaceNormal = glm::cross( sideOne, sideTwo );
mesh->normals.push_back( surfaceNormal );
}
图片中显示的当前甚至没有法线数据，因此想法是为其计算表面法线，因此是上面的代码。虽然我做了一些检查以查看索引数据是否在循环中正确加载，但我还没有找到任何东西。
我认为我整理记忆的方式也可能有问题，但我不能完全确定问题所在。万一我错过了什么，我会在我的 glVertexAttribPointer 调用中抛出：
//! Gen some buf handles
glGenBuffers( NUM_BUFFERS_PER_MESH, mesh->buffers );
//! Load the respective buffer data for the mesh
__LoadVec4Buffer( mesh->buffers[ BUFFER_VERTEX ], mesh->vertices ); //! positons
__LoadVec4Buffer( mesh->buffers[ BUFFER_COLOR ], mesh->colors ); //! material colors
__LoadVec3Buffer( mesh->buffers[ BUFFER_NORMAL ], mesh->normals ); //! normals
__LoadIndexBuffer( mesh->buffers[ BUFFER_INDEX ], mesh->indices ); //! indices
//! assign the vertex array a value
glGenVertexArrays( 1, &mesh->vertexArray );
//! Specify the memory layout for each attribute
glBindVertexArray( mesh->vertexArray );
//! Position and color are both stored in BUFFER_VERTEX.
glBindBuffer( GL_ARRAY_BUFFER, mesh->buffers[ BUFFER_VERTEX ] );
glEnableVertexAttribArray( meshProgram->attributes[ "position" ] );
glVertexAttribPointer( meshProgram->attributes[ "position" ], //! index
4, //! num vals
GL_FLOAT, GL_FALSE, //! value type, normalized?
sizeof( vec4 ), //! number of bytes until next value in the buffer
( void* ) 0 ); //! offset of the memory in the buffer
glBindBuffer( GL_ARRAY_BUFFER, mesh->buffers[ BUFFER_COLOR ] );
glEnableVertexAttribArray( meshProgram->attributes[ "color" ] );
glVertexAttribPointer( meshProgram->attributes[ "color" ],
4,
GL_FLOAT, GL_FALSE,
sizeof( vec4 ),
( void* ) 0 );
//! Now we specify the layout for the normals
glBindBuffer( GL_ARRAY_BUFFER, mesh->buffers[ BUFFER_NORMAL ] );
glEnableVertexAttribArray( meshProgram->attributes[ "normal" ] );
glVertexAttribPointer( meshProgram->attributes[ "normal" ],
3,
GL_FLOAT, GL_FALSE,
sizeof( vec3 ),
( void* )0 );
//! Include the index buffer within the vertex array
glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, mesh->buffers[ BUFFER_INDEX ] );
glBindVertexArray( 0 );
至少在正确方向上的任何一点都会受到赞赏：我不知道这些问题的常见原因是什么。
编辑：应要求发布绘制代码
glBindVertexArray( mMeshes[ i ]->vertexArray );
UBO::LoadMatrix4( UBO::MATRIX_MODELVIEW, modelView.top() );
UBO::LoadMatrix4( UBO::MATRIX_PROJECTION, camera.projection() );
glDrawElements( GL_TRIANGLES, mMeshes[ i ]->indices.size(), GL_UNSIGNED_INT, ( void* )0 );
glBindVertexArray( 0 );