# Essential Math WeblogThoughts on math for games

## 11/16/2005

Filed under: General,Personal — Jim @ 9:12 pm

First of all, my apologies for the lack of posts. Part of it was the demands of my paid work: For some time, I’ve been working on the PS2 version of Rainbow Six: Lockdown, and those of you in the know are aware that the ship date was pushed out from March to September. While most of that was just polish, doing that final 1% takes a fair amount of effort. So only recently have I felt like digging into new engineering challenges and blogging again. The other part was that I didn’t have much to write about, but I have some ideas which I’ll put up in the next few weeks.
(more…)

## 11/11/2005

### GDC Update

Filed under: General,Tutorial — Jim @ 8:51 pm

The GDC sessions have finally been announced, and I’m pretty excited about the tutorial this year. Instead of doing the usual 2-3 people talking about a variety of subjects, some of which is not their specialty, this year we have 6 people with a broad range of experience. This should allow us to have deeper coverage and present an overall better tutorial.

Here are the speakers, with their current proposed topics:

Jim Van Verth: Physics Engine Overview
Christer Ericson: Numerical Robustness
Squirrel Eiserloh: Relative Motion and Collision
Gino van den Bergen: Narrow (GJK) and Broad (Sweep and Prune) Phase Collision
Erin Catto: Constraints and Solvers
Marq Singer: Dynamic Destruction

The full session description can be found on the GDC 2006 site. Hope to see some of you there!

## 11/5/2005

### More errata

Filed under: Erratical — Jim @ 9:41 pm

A couple more errata have come in since the last update. From Tim Lowery comes:

“On page 117, the figures look mislabeled, or the axis is incorrect. For example, Figure 3.5a shows x-axis rotation, but the object is rotating around the y-axis. Likewise, for Figure 3.5b.”

In this case, the captions are correct (the intent is to go in xyz order), but the figures are reversed.

From k. avery comes:

“At the end of p. 623, cot theta should be csc theta / sec theta, not sec theta / csc theta.”

Indeed it should be. And I had thought I caught that one once before. Evasive devils, those cotangents.