exrenvmap

exrenvmap [options] infile outfile

Description

Convert an OpenEXR latitude-longitude environment map into a cube-face environment map or vice versa. Reads an environment map image from infile, converts it, and stores the result in outfile.

If the input file name contains a ‘%’ character, then an input cube-face environment map is assembled from six square sub-images that represent the six faces of the cube. The names of the six image files are generated by replacing the % with +X, -X, +Y, -Y, +Z and -Z respectively.

If the output file name contains a ‘%’ character and the program has been instructed to produce a cube-face environment map, then the output image is split into six square sub-images that are saved in six separate output files. The names of the files are generated by replacing the % with +X, -X, +Y, -Y, +Z and -Z respectively.

Options:

-o

produces a ONE_LEVEL output file (default)

-m

produces a MIPMAP_LEVELS output file (-m has no effect if the output image is split into multiple files)

-c

the output file will be a cube-face environment map (default)

-l

the output file will be a latitude-longitude environment map

-ci

the input file is interpreted as a cube-face environment map, regardless of its envmap attribute

-li

the input file is interpreted as a latitude- longitude environment map, regardless of its envmap attribute (-li has no effect if the input image is assembled from multiple files)

-w x

sets the width of the output image to x pixels (default is 256). The height of the output image will be x*6 pixels for a cube-face map, or x/2 pixels for a latitude-longitude map.

-f r n

sets the antialiasing filter radius to r (default is 1.0) and the sampling rate to n by n (default is 5 by 5). Increasing r makes the output image blurrier; decreasing r makes the image sharper but may cause aliasing. Increasing n improves antialiasing, but generating the output image takes longer.

-b

blurs the environment map image by applying a 180-degree-wide filter kernel such that point- sampling the blurred image at a location that corresponds to 3D direction N returns the color that a white diffuse reflector with surface normal N would have if it was illuminated using the original non-blurred image. Generating the blurred image can be fairly slow.

-t x y

sets the output file’s tile size to x by y pixels (default is 64 by 64)

-p t b

if the input image is a latitude-longitude map, pad the image at the top and bottom with t*h and b*h extra scan lines, where h is the height of the input image. This is useful for images from 360-degree panoramic scans that cover less than 180 degrees vertically.

-d

sets level size rounding to ROUND_DOWN (default)

-u

sets level size rounding to ROUND_UP

-z x

sets the data compression method to x (none/rle/zip/piz/pxr24/b44/b44a/dwaa/dwab, default is zip)

-v

verbose mode

-h, --help

print this message

--version

print version information