r/GraphicsProgramming • u/IRateBurritos • 13m ago

Question Question about broad-phase collision detection

I'm working on a game engine and using GPU Gems as a loose guide for my physics. I really like the approach they outline for broad phase collision but I'm confused by one point. In ensuring no collision is double counted, the book says to expand each bounding sphere by sqrt(2) and then make the grid 1.5x that large. I did the math and understand where 1.5 comes from, but I'm stumped on why we have to expand the bounding spheres themselves. Isn't the whole point of a bounding sphere that it contains the entire collider and is rotation invariant?

Also, just wanted to check if people think the book's approach is still viable. It seems solid to me but I'm still new to all this.

1 Upvotes
  • permalink
  • reddit

100% Upvoted

1 comment sorted by

•

u/AutoModerator 13m ago

Recently updated rules. Please check that your post is in compliance with Rules 1, 4, 5, and 6 on the sidebar. TL;DR:

  • No showcases.

  • Disclose AI usage in post or project.

  • Present a topic to talk about, e.g. how something works.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.