Pretty much any physics engine is going to support that.

I wish I knew why this started happening to some folks. I havent changed anything that would make it fail like that. The code in question is the same code I have been using since SP version 1 like 4 years ago.

As far as I can tell it thinks there is a group with absolutely nothing in it. Which might be possible if you really tried. But it should NOT just start happening on a known good model. Argh!

Newton supports mass and friction I just haven't exposed it to SP yet. I plan that for the next major version. And I have nothing against ODE. As I said if I had to do it over I might do it differently.

If you want to make a ODE plugin for Sketchup I can offer advice and encouragement but I dont have any spare bandwidth to spend on coding. Here is an overview of whats involved.

The first step is to link ODE to the Ruby language that SU uses for plugins. I use Ruby/DL to link to the Newton.dll. Then at runtime initialize the physics engine and then traverse the model and create physical bodies and joints for each group tagged as a physics object. Then you can use the Sketchups Tool class to wrap animation of the physics engine (the "nextFrame" calls). After each frame readback the location of all the objects in the simulation and set the groups transformation accordingly.

Its not too hard to do but the devil is in the details. For example under Newton the bodies need to be scaled and rotated into the coord system of the physics engine. But I expect ODE being more widely used will have fewer problems like this.

Chris

WTF. There is another thread about this issue. How can SP just stop working all of a sudden?????

SPIV will use 2.0. But dont expect it to be faster. The bottleneck is Sketchup rendering.

Are you trying to download the models from inside sketchup? You need to use a regular browser and download them to disk before opening.

I dont know why that model is failing for you. It works fine for me.

Again is it true that all models used to throw the error and now just this one?

@wacov said:

All this stuff is SO awesome... when you say linear/angular damping, will that act like a basic kind of air resistance?

Yes

@wacov said:

And what I'm really interested in, is if you set density to 0, what happens? Is it truly 0... i.e no weight or inertia? As long as it works ok as a noCollision object, attached to something else, then it's fine.

No. For some reason the physics engine treats objects with very low mass as static. Thats why really small objects dont move. Its lame in my opinion but not something I can change.

Depending on what you need a zero mass object for there may be something that will do what you want. I havent got it working yet but there is a new script command that will let you say where you want an object to be and it will "fly" to that location with out any sort of joint.

@wacov said:

Then with the torque and velocity; can you set them at runtime? And can you retrieve the object's current torque and velocity?

Yes.

@wacov said:

And, out of interest, isn't it now possible, with a few workarounds, to copy/paste and emit complex (jointed) objects? Just automatically connect each object with script at the beginning of the simulation, and do the same thing with emitters (if we can set an emitted object's script field...?)

Its possible. Objects that connect themselfs at start or on touching will work like that. But so far it still requires a lot of fiddly scripting. Not sure how it will turn out in the end.

I haven't exposed the emitters to the script yet. But you can do almost the same thing using the copy command.

Here is a simple teleport:
http://sketchyphysics2.googlecode.com/files/teleport2.wmv

As I said before I have no experience with Matlab and as such have no idea how to go about integrating it or even if it is possible. Also SP currently does not expose mass and friction. The physics engine supports it via "material" pairs, but the interface isn't easy to translate in to Sketchup terms.

As for ODE, when I started SP I looked at all the physics engines that were then available and chose Newton mostly because of the joint implementation. If I had it to do all over I might go with ODE or Physx but it is too late now.

Sorry
Chris

The new scripting interface is making it much easier to expose the functionality of the physics engine. Full material support will have to wait until SPIV, but you can now change object density and linear/angular damping. That means you can have one object weight more or less than an identical object.

http://sketchyphysics2.googlecode.com/files/density.avi

Orbital mechanics type stuff now works because you can set damp to 0.0. Or even set it high to make objects act like they are in quicksand.
http://sketchyphysics2.googlecode.com/files/orbit.avi

Also exposed is velocity and torque. You can make an object that starts in motion or rotating.

Teleporting is working well now. I tried to make a "portal" type object but it is proving harder than I expected.

The Newton SDK is a C/C++. It sounds like you may want to code directly to that:
http://www.newtondynamics.com/

So am I a clear; At first no models worked. But after reinstalling all except one work? And its throwing the same error?

Which model fails?

I dont know of a Sketchup Ruby API tutorial. Mostly I just look at examples. Here is the API:

http://download.sketchup.com/OnlineDoc/gsu6_ruby/Docs/ruby-classes.html

You probably want to look at Entities, Face and Edge

Here is how you add a face for example:

Sketchup.active_model.entities.add_face([[0,0,0],[10,0,0],[10,10,0],[0,10,0]])

You have a seriously hosed install somehow. The function (file_loaded?) is part of Sketchup. If that isnt working nothing else will.

I would suggest that you rename your google sketchup directory. Reinstall Sketchup then install SketchyPhysics using the installer. If that doesn't work then there must be a problem with your system.

Outstanding!! Rendering support has been one of the most requested SP features. I cant wait.

Thanks Whaat!
Chris

Not that I know of. SP uses the Newton physics SDK and it is constrained by its limitations. I dont know much about Matlab so I have no idea if it is compatible or not.

Sorry.

In theory it should be possible. But it really doesnt have much to do with SP. You would build it using the Sketchup Ruby API. But I warn you that skinning inst very easy. And doing vertex level operations (skinning) in Sketchup is really slow.

Cool! Thanks for doing this. If everyone likes it I will make it part of the next release.

Thanks!

That would do it. Make sure the installer is pointed to the right path.

Ill look into it.