2010-11-24 59 views
2

我有一些Irrlicht代码可以生成一个给定宽度和高度的矩形网格。这里是生成顶点和索引的代码:在这个网格中,边界框没有被正确设置?

int iNumVertices = (width + 1) * (height + 1); 
S3DVertex * vertices = new S3DVertex[iNumVertices]; 
memset(vertices,0,sizeof(S3DVertex) * iNumVertices); 

for(int i=0;i<=height;++i) 
{ 
    for(int j=0;j<=width;++j) 
    { 
     int iIndex = (i*(width + 1)) + j; 

     vertices[iIndex].Pos.X = i * 2.0f; 
     vertices[iIndex].Pos.Y = 0.0f; 
     vertices[iIndex].Pos.Z = j * 2.0f; 
     vertices[iIndex].Color.color = 0xFFFFFFFF; 

     vertices[iIndex].TCoords.X = i; 
     vertices[iIndex].TCoords.Y = j; 
    } 
} 

int iNumIndices = 6 * width * height; 
u16 * indices = new u16[iNumIndices]; 

for(int i=0;i<height;++i) 
{ 
    for(int j=0;j<width;++j) 
    { 
     int iIndex = ((i*width) + j) * 6; 

     int tmp_offset = j + (i * (width + 1)); 

     indices[iIndex + 0] = tmp_offset + 1; 
     indices[iIndex + 1] = tmp_offset + width + 1; 
     indices[iIndex + 2] = tmp_offset; 
     indices[iIndex + 3] = tmp_offset + 1; 
     indices[iIndex + 4] = tmp_offset + width + 2; 
     indices[iIndex + 5] = tmp_offset + width + 1; 
    } 
} 

然后,顶点和索引被添加到网和边界框被重新计算:

SMeshBuffer * buffer = new SMeshBuffer(); 
buffer->append(vertices,iNumVertices,indices,iNumIndices); 

buffer->recalculateBoundingBox(); 

然而,渲染时,边界框无处接近正确的大小:

alt text

这样做的最终结果是,网格不会被渲染时的SMA将包围盒放在相机后面。

+0

你是如何计算宽度和高度的? – casablanca 2010-11-24 01:22:21

回答

1

原来,问题是我在缓冲区而不是网格上呼叫recalculateBoundingBox()