How come the bounding box isn't being set properly in this mesh?

I have some Irrlicht code that generates a rectangular mesh given a width and height. Here is the code that generates the vertices and indices:

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

for(int i=0;i<=height;++i)
{
  开发者_运维百科  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;
    }
}

Then the vertices and indices are added to the mesh and the bounding box is recalculated:

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

buffer->recalculateBoundingBox();

However, when rendered, the bounding box is nowhere close to the right size:

The end result of this is that the mesh doesn't get rendered when the small bounding box goes behind the camera.

Turns out that the problem was that I was calling recalculateBoundingBox() on the buffer instead of the mesh.