error = glu.Build3DMipmaps(ifmt, width, height, depth, fmt, type, data)
glu.Build3DMipmaps()builds a series of prefiltered 3D texture maps of decreasing resolutions called a mipmap. This is used for the antialiasing of texture-mapped primitives.
A return value of zero indicates success, otherwise a GLU error code is returned (See glu.ErrorString for details.).
depth of data are checked to see if they are a power of 2. If not, a copy of data
is made and scaled up or down to the nearest power of 2. (If
depth is exactly between powers of 2,
then the copy of data will scale upwards.) This copy will be used for subsequent mipmapping operations described below.
For example, if width is 57, height is 23, and depth is 24, then a copy of data will scale up to 64 in width, down to 16
in height, and up to 32 in depth before mipmapping takes place.
Then, proxy textures (see gl.TexImage3D()) are used to determine if the implementation can fit the requested texture. If not, all three dimensions are continually halved until it fits.
Next, a series of mipmap levels is built by decimating a copy of data in half along all three dimensions until size 1x1x1 is reached. At each level, each texel in the halved mipmap level is an average of the corresponding eight texels in the larger mipmap level. (If exactly one of the dimensions is 1, four texels are averaged. If exactly two of the dimensions are 1, two texels are averaged.)
gl.TexImage3D() is called to load each of these mipmap levels. Level 0 is a copy of data. The highest level is log2(max(width,height,depth)).
For example, if
width is 64,
height is 16, and
depth is 32, and the implementation can store a texture of this size, the following
mipmap levels are built: 64x16x32, 32x8x16, 16x4x8, 8x2x4, 4x1x2, 2x1x1 and 1x1x1. These correspond to levels 0 through 6, respectively.
ifmt specifies the internal format of the texture image. See Internal pixel formats for details.
This can also be one of the special values 1, 2, 3, or 4.
fmt must be one of
type must be one of
Please note that this command operates directly with memory pointers. See Working with pointers for details on how to use memory pointers with Hollywood.
Please consult an OpenGL reference manual for more information.