Trebuchet simulation: is it possible?

Support Basics & Interface
1

I was just wondering if it would be possible to have a soft body and hard body simulation working in tandem to make a trebuchet animation. It should be easy enough to make a simulation of the all of the solid components, my only concern is whether or not a soft body sling could take part in the simulation somehow. I could just make a counterweight powered catapult, but that wouldn’t be a proper treb, therefore no fun.:stuck_out_tongue:

2

http://uploader.polorix.net//files/111/FlighTreb.blend

Move the Object Center of the Cube to the bottom for an even better effect.

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3

Looks good, but would you be kind enough to explain your setup to me? I’ve never used soft bodies before…:o Also, would the soft body sling be able to drag a rigid body projectile along the firing trough and fling it? (i.e. would setting softbody deflection on a UV sphere allow a soft body to drag the UV sphere?)

4

I was trying to do the same thing when building my trebuchet. This is a design I made if that helps:
http://savefile.com/files/424184
I was wondering if it was possible to simulate the beam across the main arm and counterweight I don’t know how to simulate fulcrums like that. also making the projectile come out of the sling correctly would be hard

5

but would you be kind enough to explain your setup to me?

The rope is a Curve with a CurveCircle BevObed with Softbody on the Curve. The CV’s closest to the Cube are the Goal and the whole thing is Vertex Parented to the top of the Cube. Only the Cube is Keyframed. It’s a very old file so I’ll have to scratch around in it if you want more detail.

To sling an object off of it you could try a Hook on the loose end of the Curve and have a Copy Location Constraint on the slung object then keyframe the INF IPO of the Constraint. Something like that… I’ll experiment over the weekend while it’s snowing.

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6

Grr! I’m trying to get a simple test of the rigid body parts to work, but the convex hull polytype bounds don’t seem to allow for holes in a mesh. When I run the following setup, the cylinder just shoots out of the top of the counterweight as if it were intersecting with a solid part of the mesh.
http://uploader.polorix.net//files/19/trebphys_thumb.jpg
:mad: Why can’t rigid body simulations just use the raw geometry of the mesh as the bounds like soft bodies do? Correct me if I’m wrong, but I believe Maya does it this way…