Self-shadowing in Bump and Parallax Occlusion Maps

March 19, 2007 at 3:28 am (Tips & Tricks)

Humus has a great little demo based on Chris Oat’s ambient aperture work . Oat’s stuff was used with terrain lighting in mind, but obviously it can be used on some bump maps also. This is a quick and dirty way to get some self shadowing on your bump mapped/parallax occlusion mapped surface without a bunch of extra texture accesses or aliasing. Oat’s method works by representing the unoccluded part of the hemisphere (the aperture) and the light source by spherical caps ( a direction and arc-length radius) and then computes the intersection of the two. Humus instead calculates the difference between the dot product of the aperture direction and the light direction minus the radius of the aperture. Pretty cool.

Please add this page to your RSS feed if like what you see so far.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: