Light Pre-Pass
Michael Quandt has posted a write up detailing the theory behind his Light Pre-Pass code he released for educational use previously.
KiloWatt Animation for XNA
Jwatte has tweeted news prediction of a new version of his KiloWatt animation library and Pre-release bits are here.
"This is the third-and-a-half release of the KiloWatt Animation library. It is intended as a companion to the kW X-port 3ds Max X file exporter, to be used with Microsoft XNA Game Studio. This release is for version 3.0/3.1 for Windows and Xbox 360. Sorry, no Zune support 
"
He goes on to explain how this is different to the XNA Skinning sample on the creators website
The KiloWatt Animation Library is different from the XNA Skinning sample code in several ways, including:
- KiloWatt Animation stores animation keyframes as position, rotation and scale (for a total of 10 floats), instead of the full matrix used by the Animation Components.
- KiloWatt Animation removes unnecessary keyframes (down to a tolerance that you can specify), for a usually quite significant savings in file size.
- KiloWatt Animation does interpolation between animation keyframes using quaternions, which means that slow-motion and varispeed playback will still look smooth.
- KiloWatt Animation supports composition (blending) of animations to generate the final output pose for a given Model.
- KiloWatt Animation replaces the Effect used for your Model only when you tell it to.
- KiloWatt Animation does not make any specific demands of your geometry; you can (and should) use it to animate rigid objects such as windmills, catapults etc. in addition to skinned meshes.
Code Snippet: Simple Arc Ball Camera
Roy Triesscheijn released the fruits of his hard, day filling labour in the form of a simple arc ball camera class.
Henge3D Physics Library for XNA
There’s a new Physics engine targeting the XNA FX (hat tip to to Nick Gravelyn for the discovery):
Project Description
Henge3D is a 3D physics library written in C# for XNA. It is implemented entirely in managed code and is compatible with the XBOX 360.
Overview:
- Rigid body simulation with collision detection, response, and approximated friction.
- Supports collision skins consisting of arbitrary convex polyhedra, spheres, capsules and planes. Collision detection against triangle meshes is also supported.
- Supports a number of constraints, including body point constraints, revolute joints, universal joints, prismatic joints, etc.
- Multi-threaded collision detection and collision response.
- Ability to import collision skins from Blender and potentially other modeling programs.
- Supports ragdolls using collections of rigid bodies with constraints (see the Holodeck program for examples).
sgMotion v1.0.0 Released
Tom Looman released his sgMotion library to CodePlex. Says Tom:
sgMotion is an animation library (based on XNAnimation by Bruno Evangelista) and provides full integration with both the Sunburn Engine and the Sunburn Framework.
More at the source.
The Shawn: Why do 2D worlds make sense?
Shawn Hargreaves ponders the possible reasons why 2D games are still popular: “What makes less sense to me is why our brains are so much better at doing math and physics in 2D than 3D” and causes a discussion in the comments.
Geodesic Grid, Part 3
Brian Schaeflein published part 3 of his Geodesic Truncated IcosahedronsGrid series, covering his design decisions about how to store the cells to aid pathfindig.
Geodesic Grid
Brian “JeBuS” I-Don’t-Know-His-Last-NameSchaeflein published a multi part article about Geodesic Truncated Icosahedron (part 2 is here, part 3 is pending) in C# and the XNA Framework. Geodisc Truncated Icosahedrons are “a shape made of hexagons and pentagons” that “has as many faces as needed to make it as spherical as needed, like a Geodesic Dome”.
Head over and grok the code for fun and profit.
Also note his disclaimer in the first post:
I don’t claim that my way of programming is the best way. As far as design patterns and whatnot go, my way works for me, and the code gets the job done. If anyone can offer a more “elegant” approach to anything I’m doing, I’m all ears.
Want to get a free XNA book by donating to Child’s Play?
With the release of his new e-book (XNA 3D Primer) MVP Michael Neel runs a limited campaign that lets you get his book for free if you donate to Child's Play.
Of course, you can also get the book at the normal price, but it's still a very nice gesture. Read all about his initiative here.
GPU Geometry Map Rendering
Things not always go as smoothly as you want in the world of GPU programming, as shown by Dave CharlieCarlile from Crappy Coding. He tried to move the code for creating procedural planets from the CPU to the GPU, and then posted his findings. It's a very interesting read, and at the end he promises a comeback with more details about using PIX to debug his problems.
