# Monthly Archives: September 2011

## Geometric Primitives Lectures

I’m going to be out of town on September 27-30, 2011 presenting two papers at GAMEON-NA, so here are videos of the lectures that I would have given to my Game Math and Physics class at the University of North … Continue reading

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## Gimbal Lock

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## Detecting Whether Two Convex Polygons Overlap

In a previous post I described how to tell whether two axially aligned bounding boxes (AABB’s) intersected. The solution was presented as a process of elimination: if box A is to the left of B, to the the right of … Continue reading

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## Detecting Whether Two Boxes Overlap

Questions asked on job interviews also make for interesting blog post topics. (And very rarely, they are also practical!) This post discusses one of my favorite interview questions: “How can you tell if two axially-aligned 2D boxes intersect?” The adjective … Continue reading

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## Composing Rotations

Here’s why programmers don’t need to remember the details of rotating around an arbitrary axis: Rotations are closed under composition. All you need to do is compose rotations around the object’s cardinal axes.

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## Vectors Just Want To Be Free

Remember, while we may draw vectors at a particular position (for example with their tails at the origin), they really don’t have a sense of place. All they have is a magnitude and a direction. If you’re unclear on the … Continue reading

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## Lecture Notes Being Alpha Tested

I have lecture notes for all except the last 3 chapters, but I’m not quite ready to release them yet. I’m alpha-testing them in my Game Math and Physics class (see http://larc.unt.edu/ian/classes/fall11/csce4215/) to make sure that they’re just right. More … Continue reading

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## 2nd Edition Coming In September

Preorder it right now!

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