GenerateMipMaps3D

DirectXTex

Generates mipmaps for a 3D volume texture from a set of images representing the slices.

This generates mipmaps for 3D dimension textures (a.k.a. volume textures). For 1D and 2D dimension textures, see GenerateMipMaps.

HRESULT GenerateMipMaps3D( const Image* baseImages, size_t depth,
    TEX_FILTER_FLAGS filter, size_t levels,
    ScratchImage& mipChain );

HRESULT GenerateMipMaps3D( const Image* srcImages, size_t nimages,
    const TexMetadata& metadata,
    TEX_FILTER_FLAGS filter, size_t levels,
    ScratchImage& mipChain );

Parameters

baseImages/srcImages: The mipmap chain is created by repeatedly down-sizing the slices of base images. The first level of the resulting mipChain is set to a copy of the input baseImages.

depth: The Z dimension of the volume texture which is also the number of slices in the baseImages array.

filter: See Filter Flags. Note that for non-power-of-2 depth volume maps, only TEX_FILTER_TRIANGLE will give the expected results. It therefore defaults to Triangle for non-pow-of-2 volume maps, otherwise it defaults to Fant/Box.

levels: Number of mip map levels including base. A value of 0 indicates creating a full mipmap chain down to 1x1x1.

Example

ScratchImage baseImages;

...

ScratchImage mipChain;
hr = GenerateMipMaps3D( baseImages.GetImages(), baseImages.GetImageCount(),
    baseImages.GetMetadata(), TEX_FILTER_DEAFULT, 0, mipChain );
if ( FAILED(hr) )
    ...

Remarks

This function does not operate directly on block compressed images. See Decompress and Compress.

This function cannot operate directly on a planar format image. See ConvertToSinglePlane for a method for converting planar data to a format that is supported by this routine.

Each miplevel of a 3D volume texture is half the size in width & height and half the number of slices of the one above to a minimum of 1.

This function does not make use of WIC for resizing since volume textures require 3D filtering methods.

Note: All slices in a miplevel must be in contiguous memory for working with Direct3D, which is how ScratchImage is implemented.