Chipmunk Physics

pTymN wrote:Good greif thats neat. How are you doing the ropes? Are the links carefully arranged to not overlap, or did you come up with some way to make a "solid" rope that allows overlapping links?

Don't know how he did it, but I made collision groups to prevent self collisions of jointed objects consisting of many bodies. You could also possibly do a hybrid circle/segment shape if you wanted to allow the rope to self collide.

I'd probably go with the former and use slide joints to the two closest links. That way you've got a semi flexible rope that can coil itself up.

Hi, I'd really love to test that code. Is there an svn somewhere ? a home page with sources ?

I would be happy to be a beta tester if you need.


Congratulations !

Bruno
http://brunetton.tuxfamily.org/

pTymN wrote:Good greif thats neat. How are you doing the ropes? Are the links carefully arranged to not overlap, or did you come up with some way to make a "solid" rope that allows overlapping links?

Looking through the documentation, it doesn't specify how the pivot joint affects the two bodies that are connected by it. If the two bodies have shapes that are overlapping when the pivot joint is made, will they collide? (they shouldn't!)

to make a rope that does not collide with its own parts you'd just need to add each link to the same group.

Is the game still alive

Sorry for the long absence, but I was really busy over the last months. The game is still alive and now available here. To answer the other questions:
The ropes simply are made by using spheres and linking them with a pivot joint. I got the idea for them from the joint demonstration. The number of circles used for every body is variable, but i figured out that using just one sphere per body gets computationally intense really soon, so i put 3-5 of them together to form every part of the rope. The game supports both, collision with and without the collision groups, but most of the time I let the rope collide with itself as it looks better. You can set the collision group for the whole rope in the editor.

Good to see Chipmunk being used in commercial projects.
What more proof is there that it is a resounding success?

Wow, just looked at the videos on Youtube. That looks so cool! Especially the escapement one.

I'm interested in how you did the cogs. Are they just rigid bodies in the shape of cogs? Or have you made some optimisations?

I hope it sells well. I'm sure it will; I'd be first in line to buy a copy if I used Windows.

Heh, those videos were made by my father, he is currently experimenting with the game a bit.
Yeah, the cogs are just simple rigid bodies. The only difficulty is to align them properly, otherwise they will jam. At first I tried to draw them by hand, but as I figured out that I can't even draw a circle that big I decided to write a function to create them. In the game editor you have the ability to create them via a simple menu. With that functions you can create a lot of different shapes, which is really cool.

I still hope, that parallels or vmware will implement a good DX emulation in the future. With parallels it will run, but the graphics are quite messed. Didn't find someone to test it on vmware, but with bootcamp it runs normally.

That's really awesome. I've always wanted to try cogs, but I assumed they'd be too complicated to work properly. Looks like yours work well though.

Man, I never thought of doing half of this stuff with Chipmunk. That's amazing.

I should really look through some old books on building simple machines.