C++ 优化地形渲染内存

我想知道（我很确定有）是否有更好的方法来处理我填充到顶点/索引缓冲区的数据。此时，地形中顶点的结构如下所示：

struct VertexType
    {
        D3DXVECTOR3 position;
        D3DXVECTOR2 texture;
        D3DXVECTOR3 normal;
    };

每次游戏开始时，我都会随机生成地形，并根据这个高度贴图计算法线和纹理坐标。最后，我以这种方式填充顶点阵列：

// Calculate the number of vertices in the terrain mesh.
m_vertexCount = (m_terrainWidth - 1) * (m_terrainHeight - 1) * 6;

// Create the vertex array.
m_vertices.resize(m_vertexCount);

// Initialize the index to the vertex buffer.
index = 0;

// Load the vertex and index array with the terrain data.
for(j=0; j<(m_terrainHeight-1); j++)
{
    for(i=0; i<(m_terrainWidth-1); i++)
    {
        index1 = (m_terrainHeight * j) + i;          // Bottom left.
        index2 = (m_terrainHeight * j) + (i+1);      // Bottom right.
        index3 = (m_terrainHeight * (j+1)) + i;      // Upper left.
        index4 = (m_terrainHeight * (j+1)) + (i+1);  // Upper right.

        // Upper left.
        tv = m_heightMap[index3].tv;

        // Modify the texture coordinates to cover the top edge.
        if(tv == 1.0f) { tv = 0.0f; }

        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index3].x, m_heightMap[index3].y, m_heightMap[index3].z);
        m_vertices[index].texture = D3DXVECTOR2(m_heightMap[index3].tu, tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index3].nx, m_heightMap[index3].ny, m_heightMap[index3].nz);
        index++;

        // Upper right.
        tu = m_heightMap[index4].tu;
        tv = m_heightMap[index4].tv;

        // Modify the texture coordinates to cover the top and right edge.
        if(tu == 0.0f) { tu = 1.0f; }
        if(tv == 1.0f) { tv = 0.0f; }

        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index4].x, m_heightMap[index4].y, m_heightMap[index4].z);
        m_vertices[index].texture = D3DXVECTOR2(tu, tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index4].nx, m_heightMap[index4].ny, m_heightMap[index4].nz);
        index++;

        // Bottom left.
        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index1].x, m_heightMap[index1].y, m_heightMap[index1].z);
        m_vertices[index].texture = D3DXVECTOR2(m_heightMap[index1].tu, m_heightMap[index1].tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index1].nx, m_heightMap[index1].ny, m_heightMap[index1].nz);
        index++;

        // Bottom left.
        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index1].x, m_heightMap[index1].y, m_heightMap[index1].z);
        m_vertices[index].texture = D3DXVECTOR2(m_heightMap[index1].tu, m_heightMap[index1].tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index1].nx, m_heightMap[index1].ny, m_heightMap[index1].nz);
        index++;

        // Upper right.
        tu = m_heightMap[index4].tu;
        tv = m_heightMap[index4].tv;

        // Modify the texture coordinates to cover the top and right edge.
        if(tu == 0.0f) { tu = 1.0f; }
        if(tv == 1.0f) { tv = 0.0f; }

        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index4].x, m_heightMap[index4].y, m_heightMap[index4].z);
        m_vertices[index].texture = D3DXVECTOR2(tu, tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index4].nx, m_heightMap[index4].ny, m_heightMap[index4].nz);
        index++;

        // Bottom right.
        tu = m_heightMap[index2].tu;

        // Modify the texture coordinates to cover the right edge.
        if(tu == 0.0f) { tu = 1.0f; }

        m_vertices[index].position = D3DXVECTOR3(m_heightMap[index2].x, m_heightMap[index2].y, m_heightMap[index2].z);
        m_vertices[index].texture = D3DXVECTOR2(tu, m_heightMap[index2].tv);
        m_vertices[index].normal = D3DXVECTOR3(m_heightMap[index2].nx, m_heightMap[index2].ny, m_heightMap[index2].nz);
        index++;
    }
}
// shrink heightmap because its no longer in use...
m_heightMap.clear();
m_heightMap.swap(m_heightMap);

//计算地形网格中的顶点数。
m_顶点计数=（m_地形宽度-1）*（m_地形高度-1）*6；
//创建顶点数组。
m_顶点。调整大小（m_顶点计数）；
//初始化顶点缓冲区的索引。
指数=0；
//使用地形数据加载顶点和索引数组。
对于（j=0；j地形大小为2048的地形，需要2048（宽）*2048（长）*8（#浮点）*4（每个浮点字节），大约128MB。这是一个不错的内存块，但本身并不不合理

我不明白四叉树代码应该做什么。看起来您正在创建另两个几何体副本？为什么要这样做？
四叉树的每个节点都有一个允许包含多少顶点的限制。我有一个“主顶点阵列”wich保存地形的所有顶点。在这个四叉树代码中，我对这个数组进行测试，以获得这个节点中的顶点。然后，我用这些顶点填充每个节点的缓冲区。好的，我想我明白了。为什么不创建一个四叉树结构，其中包含两个三角形，并将指向该结构的指针存储在四叉树中除了复制数据，你的意思是：“节点->顶点数组[index].x=（*m_顶点列表）[vertexIndex].position.x；”？我保存此文件是为了使基于高度的移动更有效。我正在检查我当前所在的节点，然后检查该节点顶点阵列的高度，以获得我当前所在的高度。否则，我不太理解您的建议。感谢您。我还猜测，由于我使用6个顶点，每个四边形，即128MB*6。正如我已经说过的，我目前不知道如何解决我创建的heightmap和四叉树之间的连接。我的意思是，不是在每个节点中放置一个顶点数组，而是放置一个vertextype对象指针数组
node->triangleCount = numTriangles;

// Calculate the number of vertices.
vertexCount = numTriangles * 3;

// Create the vertex array.
vertices = new VertexType[vertexCount];

// Create the index array.
indices = new unsigned long[vertexCount];

// Create the vertex array.
node->vertexArray = new VectorType[vertexCount];

// Initialize the index for this new vertex and index array.
index = 0;

// Go through all the triangles in the vertex list.
for(i=0; i<m_triangleCount; i++)
{
    // If the triangle is inside this node then add it to the vertex array.
    result = IsTriangleContained(i, positionX, positionZ, width);
    if(result == true)
    {
        // Calculate the index into the terrain vertex list.
        vertexIndex = i * 3;
        // Get the three vertices of this triangle from the vertex list.
        vertices[index].position = (*m_vertexList)[vertexIndex].position;
        vertices[index].texture = (*m_vertexList)[vertexIndex].texture;
        vertices[index].normal = (*m_vertexList)[vertexIndex].normal;
        indices[index] = index;
        // Also store the vertex position information in the node vertex array.
        node->vertexArray[index].x = (*m_vertexList)[vertexIndex].position.x;
        node->vertexArray[index].y = (*m_vertexList)[vertexIndex].position.y;
        node->vertexArray[index].z = (*m_vertexList)[vertexIndex].position.z;
        index++;
        vertexIndex++;

        vertices[index].position = (*m_vertexList)[vertexIndex].position;
        vertices[index].texture = (*m_vertexList)[vertexIndex].texture;
        vertices[index].normal = (*m_vertexList)[vertexIndex].normal;
        indices[index] = index;
        node->vertexArray[index].x = (*m_vertexList)[vertexIndex].position.x;
        node->vertexArray[index].y = (*m_vertexList)[vertexIndex].position.y;
        node->vertexArray[index].z =(*m_vertexList)[vertexIndex].position.z;
        index++;
        vertexIndex++;

        vertices[index].position = (*m_vertexList)[vertexIndex].position;
        vertices[index].texture = (*m_vertexList)[vertexIndex].texture;
        vertices[index].normal = (*m_vertexList)[vertexIndex].normal;
        indices[index] = index;
        node->vertexArray[index].x = (*m_vertexList)[vertexIndex].position.x;
        node->vertexArray[index].y = (*m_vertexList)[vertexIndex].position.y;
        node->vertexArray[index].z = (*m_vertexList)[vertexIndex].position.z;

        index++;
    }
}

// Set up the description of the vertex buffer.
vertexBufferDesc.Usage = D3D11_USAGE_DEFAULT;
vertexBufferDesc.ByteWidth = sizeof(VertexType) * vertexCount;
vertexBufferDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
vertexBufferDesc.CPUAccessFlags = 0;
vertexBufferDesc.MiscFlags = 0;
vertexBufferDesc.StructureByteStride = 0;

// Give the subresource structure a pointer to the vertex data.
vertexData.pSysMem = vertices;
vertexData.SysMemPitch = 0;
vertexData.SysMemSlicePitch = 0;

// Now finally create the vertex buffer.
device->CreateBuffer(&vertexBufferDesc, &vertexData, &node->vertexBuffer);

// Set up the description of the index buffer.
indexBufferDesc.Usage = D3D11_USAGE_DEFAULT;
indexBufferDesc.ByteWidth = sizeof(unsigned long) * vertexCount;
indexBufferDesc.BindFlags = D3D11_BIND_INDEX_BUFFER;
indexBufferDesc.CPUAccessFlags = 0;
indexBufferDesc.MiscFlags = 0;
indexBufferDesc.StructureByteStride = 0;

// Give the subresource structure a pointer to the index data.
indexData.pSysMem = indices;
indexData.SysMemPitch = 0;
indexData.SysMemSlicePitch = 0;

// Create the index buffer.
device->CreateBuffer(&indexBufferDesc, &indexData, &node->indexBuffer);

// Release the vertex and index arrays now that the data is stored in the buffers in the node.
delete [] vertices;
vertices = 0;

delete [] indices;
indices = 0;