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Make Your Own IBL Images On The Cheap

For use with Poser 6 or 7

Poser's Image-Based Lighting can bring great realism to your scenes- and now you can add custom lighting images to your library without spending a lot of money.Do-It-Yourself Image-Based Lighting

Poser 6 added quick and easy image-based lighting to the Poser user's toolkit, and it included several useful images for use with the image-based lighting model. Some users may want to create their own images to replicate particular lighting setups not found in the default set; this isn't at all difficult.

Image based lighting in Poser and other 3D applications uses a special type of image known as a light probe, which provides the image data with which to light the scene. Light probes are typically created with digital cameras and reflective spheres- the gazing balls available from garden stores provide high-quality light-probe images.

Gazing balls are bulky, heavy, expensive and can be delicate, however; this tutorial will show how to use simple, inexpensive equipment to shoot light probes that give fine results in Poser.

One thing to mention before delving into the mechanics of creating light probes- Poser 7 now supports high dynamic range images (HDRI) for light probes; these images sample a wider range of light and dark values than conventional images, thus providing more subtle and realistic detail to the lighting. Poser 6 doesn't support (or require) HDRI light-probes; a simple JPEG is quite sufficient- but if you want to create HDRI files using this method, it can be done if your camera allows you to adjust its exposure settings and save images in TIFF or RAW format.

What You'll Need

1. A digital camera. Even a consumer point-and-shoot digital camera will do to create JPEG files; in a pinch a variety of other cameras (cell phone cameras, Polaroids used in conjunction with a scanner, etc.) can produce acceptable results when creating JPEG files. For this tutorial I used a Nikon Coolpix 775, an older 2-megapixel point-and-shoot. Creating HDRI files as noted above requires a camera capable of exposure adjustment and TIFF or RAW support.

2. A mirrored ball. Any mirrored ball will work, but to keep the costs to a minimum I used silver Christmas ornaments. The glass ones produce the cleanest images but they're fragile- you don't want to haul out your camera bag and find your mirror ball in fragments. I used plastic ornaments in two sizes- 6" and 2" diameter; they're light and sturdy.

3. (optional but useful) a tripod- or even two tripods. Tripods can be used both to hold your camera and keep it steady, and to hold the mirrored ball itself (to make it easier to position it.) Mini-tripods, like the one used here, retail for under $20 and pack away easily.

4. A computer with image editing software (Photoshop, Paintshop Pro, etc.) You'll want to crop the digital picture to a square containing the image of the ball (and perhaps edit yourself out of the image as well.) Creating HDRI files requires a full version of Photoshop CS2 or an equivalent image editor, as you'll be producing large, complex HDRI files; inexpensive editing programs typically won't do that.

With the camera, mirror ball and tripod(s) in hand, it's time to go shoot some light probes. You'll want to avoid using the flash whenever possible, since you're trying to capture the ambient lighting of the scene. Use your imagination when picking locations- sometimes the strangest situation can make a dramatic lighting model.

The Photography

When you find a good lighting situation, set up your tripod (if you have one) and attach your mirror ball to it. If you're using a plastic ornament, you can usually pop the top off (as shown in image 1 above) and screw the threaded camera-mount on the tripod into the resulting hole. Otherwise you may need to improvise; try to keep the mirror ball steady with as little of it obscured as possible. Set the camera up as far back from the ball as possible, using the zoom to correct for distance and supporting the camera on another tripod if you have one. If you can, use the self-timer to let yourself get out of the picture.

You'll want to take several shots using different exposures and perhaps from different angles, to give yourself plenty of raw data to work with. Don't rush- it's better to take too many pictures than to get home, load the images into the computer and find that nothing you have is just right.

If you intend to produce HDRI files, for each lighting setup you'll want to shoot three to five images (at least)- one overexposed a bit, to capture detail in the shadows, one underexposed to capture details in very light areas, and one at the optimal exposure for the scene (and perhaps a couple of others to provide a smoother tonal range from lightest to darkest.)

Processing the Light-Probes

After shooting the pictures, pick the ones you want to keep and crop them to the edges of the mirror ball. Leave the corner areas alone; they contain information that will be used. Save the resulting square images as JPEG files; Poser isn't particularly finicky about the size or quality of its JPEG light probes, but I like to use at least 70% (medium) quality files saved at around 500-750 pixels on a side. Anything much larger will get subsampled down anyway.

For HDRI files, you'll need to combine each set of TIFFs or RAW files into a single file in .HDR format- a process somewhat beyond the scope of this tutorial. For some tips on how to do this, and some worthwhile background on HDRI, take a look at .

Place the light-probe images where you'll be able to find them (I have an "IBL images" folder inside the Poser 6/Runtime/textures folder that I like to use); for instructions on how to set up and use image-based lights in Poser 6 or 7, see .