This plugin “bakes” a texture from one object to another, allowing you to transfer texture data between two models with the same geometry but different texture coordinates–without having to re-paint the texture bitmap! This is useful if you start to paint a texture, and change your mind later about the UV map; or for games when you can’t change the layout of the map for technical reasons, but would like different UVs for convenience during painting. It’s also good for fitting text onto a warped surface or other projections that would be difficult or impossible to paint by hand.

Download the plugin. (Requires Windows XP, AC3D 6.2 or above.)

This new wearable motion capture system is so compact, it can even be used to capture movement in otherwise impossible environments like behind the wheel of a car!

[youtube:http://www.youtube.com/watch?v=V0yT8mwg9nc 350 292]

The most interesting part? The authors claim to have built their prototype from off-the-shelf components for only around $3K. Read the paper here.

Ambient occlusion is a lighting technique that is commonly used to create soft shadows on objects. Ambient occlusion isn’t used to create the type of shadows that are cast from objects with a light shining directly on them. Instead, ambient occlusion generates the type of deep shadows that appear in the corners or creases of things, where it is hard for the light to reach.

Technically speaking, ambient occlusion is a global illumination technique. However, in common usage of the term it is often referred to as a cheap alternative to global illumination. To clear up any confusion, what most renderers refer to as “global illumination” is actually an amalgamation of several techniques such as radiosity, metropolis light transport, image-based lighting or photon mapping. The actual techniques used differ slightly from renderer to renderer. Some renderers include an ambient occlusion term as part of their global illumination calculation; others do not.

Like most global illumination techniques, ambient occlusion is dependent on the other geometry in the scene. Ambient occlusion on its own generates less realistic lighting than “full” global illumination. However, ambient occlusion is much faster and less complex to calculate than other methods which is why it is still popular among game developers and in production animation.

(Left) Without Ambient Occlusion. (Right) With Ambient Occlusion
Click for larger image.

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This step-by-step guide will show you how to make a torus in AC3D using the Revolve tool.

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A friend at work just showed me this, and boy is it cool. “Seam Carving” is a new algorithm for image retargeting. Image retargeting is an alternative to scaling and cropping, but it is content-aware. Scaled images suffer from the problem that the re-sized content may be too small to see. Cropped images may eliminate important content. Image retargeting solves both problems by keeping the image elements the same size and simply eliminating the “unimportant” parts of the image.

Graphic artists occasionally modify images this way by hand when doing page layouts for magazines–think of it like a visual form of copy-fitting–but an automated approach opens a world of possibilities. The number of of potential practical applications are immense, and include everything from dynamic web page re-flowing to widescreen-to-standard aspect texture fitting for games.

[youtube:http://www.youtube.com/watch?v=vIFCV2spKtg 350 292]
A better version of the video as well as the research paper can be found on Dr. Shamir’s home page. What’s really neat is how straight-forward the method seems to be. The paper is well worth the read if you are interested in graphics algorithms.

If you’d like to play around with this technique on your own images, someone’s already implemented the algorithm in Flash.