Bullet Physics Collision Margins and Shapes
Why Blender Stack Exchange recommends it
Blender Stack Exchange answerers point people to it as the go-to reference for Bullet collision margins, shapes and compound bodies in the Blender game engine and rigid body setups.
Recommended by 2 people across 2 different months, 2014 to 2017.
What it is
A 34-minute walkthrough by Phymec on how collision margins and collision shapes work in the Bullet physics engine. It covers primitives, convex hulls, compound rigid bodies, and margin tricks such as bevelled cylinders and manual convex decomposition, with examples in Blender.
What people said
Recommends mike2008and2008 · 2014-08 · Blender Stack Exchange · on “Keep objects from intersecting each other when positioning them?”
In the latest version of Blender, right now it is 2.71, there is a selection called mesh in the collision tab. This seems to work very well for most active rigid body objects. There is a tutorial by PHYMEC on YouTube addressing this very issue and he goes into great depth about the sphere of influence of an object on another object: Great video on collisions for rigid bodies [this video]
Recommends Jaroslav Jerryno Novotny · 2014-12 · Blender Stack Exchange · on “Creating a trailer rig”
Looks like you need to use the BGE Bullet physics engine. Set the objects as Rigid bodies, then setup constraints between them of type Rigid Body Joint. This way your objects will behave like you expect them to. Scripting similar behavior would be lot of work. You will need also some collision meshes like ground. There are some videotuts on the net how to setup this, this one [this video] is good.
Cites philipp · 2014-10 · Blender Stack Exchange · on “Compound rigid body in cycles”
I would like to create a compound rigid body. I had a look at this video [this video] , therein compound bodies were created by sampling primitive bodies together. The collision shape was set to a primitive like box or capsule. Than these bodies were all parented an so connected to each other and acted as a complex body. However, the video used the blender-game mode, where the physics panel looked different to the one available in cycles-mode. In opposite to the video there is no option to set the collision bounds to compound. But probably some images to explain: That hook is the a hierarchy of 9 cylinders, each is a rigid body. That is how it looks like in the outline: This is the view of the ph
Cites desinghkar · 2015-07 · Blender Stack Exchange · on “What is the difference between blender render and blender game?”
I have to simulate rigid body physics simulation that is close to the real objects. Its about free fall of objects from initial random position onto a table. I am new to blender so I started my project in blender render and have been working on it. But I see that in certain tutorials [this video] , they use blender engine. So I wasn't quite sure about the difference of these two modes. When to use which? What is right setting for my project?
Cites sdfgeoff · 2017-08 · Blender Stack Exchange · on “How can I make a tower of stacked boxes stable in the game engine?”
You can build quite stable towers of stacked boxes. The tricks: Convex Hull. This is the best all-round physics shape. It's the most "stable" with the exception of capsule and sphere - which are unsuitable here. Yes, I've found convex hull better than cube type. Big collision margins. These help bullet to figure out how to respond to intersecting objects. If you separate your physics and graphics mesh you can make these unnoticable. If you really need to, increase your physics substeps in the world panel. A very good reference video about bullet is this one by phymec: [this video]