isixpack utility

Generates an environment/reflection map from six images representing the six sides of a cube, or a cross image.


  1. isixpack [-u usize] [-v vsize] front right back left top bottom outimage

    Combines six separate images into an environment/reflection map. The images should be rendered with viewing angles of 90 degrees, a square resolution (typically 256 x 256), and a square pixel aspect ratio.

    • If the output format is .rat, the command generates a multi-file cubic environment map.

      You can retrieve each individual image from the .rat file using iconvert -i image_num reflect.rat outimage.

    • If the output format is not .rat, the command generates a single lat-long environment map.

  2. isixpack cross_image.pic map.rat

    Alternative to using separate images for each side of the cube, takes a single image which is laid out in the shape of a cross (similar to the example images here). This generates a single cubic .rat file.

    Lay out the cross image as either:



  3. isixpack map.rat cross_image.pic

    Converts an environment/reflection map back into the corresponding cross image.


Default output file resolution is 1024 x 512.

-u usize

Horizontal output resolution.

-v vsize

Vertical output resolution.


Anti-alias the output with 3 x 3 Super sampling.


Generate a cubic environment .rat file from front, right, back, left top, and bottom images:

isixpack frnt.pic rite.pic back.pic left.pic top.pic bot.pic map.rat

Generate a cubic environment .rat file from a cross HDR image:

isixpack kitchen_cross.hdr kitchen.rat

Display a cubic environment map:

isixpack kitchen.rat ip

To make a .rat file which is a lat-long representation of the environment map, the environment map needs to be generated as a non-rat format initially:

isixpack front right back left top bottom stdout | iconvert stdin out.rat