Erin Catto and Valve's Box3D Engine Sparks Debate Over Future of Game Physics

Post date: July 6, 2026 · Discovered: July 6, 2026 · 4 posts, 0 comments

Erin Catto, alongside Dirk Gregorius from Valve, has released Box3D, a new 3D physics engine based on Valve's Rubikon and used in Facepunch's s&box. The engine has been in use for about a year, showcasing its practical application in game development.

Commenters are divided. Some praise Box3D as a revolutionary leap in physics engine technology, citing Catto's 20 years of experience and the engine's potential to reshape game development. Others speculate that the mention of Ragnarok, an optimization engine similar to Box3D, might signal Valve's next major physics engine, possibly for future projects like HL3. Skepticism surrounds the implications for Valve's upcoming games.

The consensus is that Box3D represents a significant advancement in physics engine development, with strong support for its practical use in s&box. However, the mention of Ragnarok has sparked speculation and debate about Valve's future plans, highlighting a divide between those who see it as a natural progression and those who are wary of unconfirmed rumors.

Key Points

#1Box3D is a revolutionary new physics engine developed by Erin Catto in collaboration with Dirk Gregorius from Valve.

uGreyCat highlights the engine's development and its potential to reshape game development.

#2Box3D is based on Valve's Rubikon engine and has been in use for about a year in Facepunch's s&box.

uGreyCat notes the practical application of Box3D in s&box, demonstrating its real-world impact.

#3The mention of Ragnarok raises speculation about Valve's next physics engine.

uGreyCat suggests that Ragnarok could be a new engine for future Valve games, possibly linked to HL3.

#4Commenters are skeptical about the implications of Ragnarok for future Valve games.

Some users question whether Ragnarok is a genuine development or a red herring.

Source Discussions (4)

This report was synthesized from the following Lemmy discussions, ranked by community score.

78
points
Box3D | A revolutionary new physics engine developed by Erin Catto in collaboration with a Valve dev
[email protected]·13 comments·7/6/2026·by GreyCat·x.com
37
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Box3D | A revolutionary new physics engine developed by Erin Catto in collaboration with a Valve dev
[email protected]·1 comments·7/6/2026·by GreyCat·x.com
33
points
Box3D | A revolutionary new physics engine developed by Erin Catto in collaboration with a Valve dev
[email protected]·3 comments·7/6/2026·by GreyCat·x.com
14
points
Box3D | A revolutionary new physics engine developed by Erin Catto in collaboration with a Valve dev
[email protected]·2 comments·7/6/2026·by GreyCat·x.com