@ampa said:

Noticed one other bug: pressing Ctrl+Z (Undo) while the simulation is running causes seriously bad things to happen! Can Undo be disabled temporarily?

Yeah, Ill mark it as a bug.

@ampa said:

1. Create rings (torus) and arrange them so that they interlock in 3d space. Why does this not work? I assigned Shape:convexhull, but this is obviously not correct.

A whole torus marked as convexhull will really resemble a solid wheel. If you want to create linked torus you need to break each segment of the torus apart into a convex hull and then group all the pieces. I did it once and it takes a while.

@ampa said:

3. A different sort of chain… Created a linear array of cubes and inserted a ball joint between each one. At this stage I have a vertical column of swinging cubes, but they all act independently. And I can't work out how to correctly group the joints with the cubes to create a single chain of linked cubes. What is the correct way to do this?

Group each of the ball joints with one of its two connected links and then use the JCT tool to connect the other link to the ball joint.

I should warn you that the ball joints aren't very stable when you connect them like this. The chain will fly wildly out of control if you try to move it too fast. This is a limitation of the underlying physics engine.

Chris

@ampa said:

Can I use a spring like a piece of elastic?

What I would like is that the model starts with the elastic stretched, so that once the simulation begins it will try to shrink to zero length (or some other predefined minimum length) pulling any attached object with it.

Where-as the spring seems not to exert any force on attached objects until it is either streched or compressed from the start position.

Ampa

It doesn't do that yet. Ill add it to my todo list.

Thanks Ampa.

There are some pretty good user generated demos popping up on 3d warehouse. Here are a few good ones!
http://sketchup.google.com/3dwarehouse/details?mid=f27b91714ea5752a87d6d7c29947ae22
http://sketchup.google.com/3dwarehouse/details?mid=4ceb45eacc729c5ea611269c93d910
http://sketchup.google.com/3dwarehouse/details?mid=fefb0ae5c3399f426e49a9db8e76daf1
http://sketchup.google.com/3dwarehouse/details?mid=d972bcb8198c5770ac03d4486f1f7520

And a good YouTube video:
http://www.youtube.com/watch?v=YQquRx7rmkk

@unknownuser said:

is there a way to convert a regular group or component into sketchy solids?

Right click it and use the Set Shape menu.

@unknownuser said:

Very cool plug in!
If I move the sketchyphysics tool window any other toolbars that are open on my second monitor close.

Hm. Thats wierd. Ill look into it.

Chris

You can adjust the size of the world under Plugins->Physics Settings. Adjust world scale to make it bigger or smaller. Note if you make it too big small things will stop working.

Chris

@unknownuser said:

Chris,
That is nothing short of amazing. I'm awestruck. I'm curious as to why and what it took (in general terms) to create this.

Mark

Thanks Mark.

The why is because its fun. I like making things that actually behave the way you'd expect.

What it took was a good physics engine (newton) and a lot of work. I have been working on it on and off for over 2 years. Its currently around 10k lines of ruby but I have probably written and discarded 20k.

Some of that 10k is code that isn't even enabled yet. SketchyReplay for example records animations and features some non-linear editing. Here is an example. Note the camera behavior and the rewind stuff at the end.

Chris

@namza said:

@cphillips said:

@namza said:

i did that funny work
you need the last version of sketchyphysics http://code.google.com/p/sketchyphysics/wiki/LatestVersion

Very cool. That is the simplest self moving machine I have seen.

Chris

i made it afer a lost of test. The problem is that now i CAN'T ( !!) reproduce this machine. It goes with join and groups but all depends of what do i have to join ans what do i have to group ...and in wich order .....

You can use the joint connection tool to examine the way the joints are connected. In this case each of the 3 cylinders is grouped with a hinge. And the bars are just connected to the hinges.

Joint connections can be confusing at first.

@namza said:

i did that funny work
you need the last version of sketchyphysics http://code.google.com/p/sketchyphysics/wiki/LatestVersion

By the way. I see you made your track out of blocks. That is fine, but you can also just edit the floor. Any staticmesh (like the floor) can be edited at a per face level and will still work.

[url=http://www.sketchucation.com/forums/scf/sas/SketchyPhysics/avance3c-track.skp:33txugzx]avance3c-track.skp[/url:33txugzx]

@namza said:

i did that funny work
you need the last version of sketchyphysics http://code.google.com/p/sketchyphysics/wiki/LatestVersion

Very cool. That is the simplest self moving machine I have seen.

Chris

@whaat said:

I like this script so much, I thought I'd do a tribute...Indigo style!

301 Moved Permanently

(www.sketchucation.com)

Whaat

That looks really cool! It will be nice when we can finally do physics and ray tracing in real time.

@haggai said:

I am doing this but what i meant is that even when I lift up the object it is hard to control them, they are like hanging on a string and swinging as i move.

Oh, I see. I tried it so the object moved faster and it didnt work very well. The problem is the object flys around the scene too fast. Say you drag a cube from one side of the screen to the other. Depending on how far out you are zoomed the object can be moving hundereds of miles per hour. If it bumped into anything along the way that object would go flying.

Ill make it adjustable in a future version and you can try it.

And I agree, the controls could be better.

Chris

@haggai said:

one question I have for now, is there a way to control how to "grab" the objects in a way that we can for example grab a cmu block and put it on an other one with presision. When I tried they seem to be floating in the air as I carry them? I will keep trying.

By default the object will try to move only horiziontaly. Hold down CTRL to drag up and down.

There is a tutorial of sorts here:
http://code.google.com/p/sketchyphysics/wiki/Tutorials

Chris

Any other comments or feedback?

Has anyone used the SketchySolids toolbar? I am thinking that it is almost worthy of being a separate plugin.

Chris

@unknownuser said:

test my architecture... wind shear, snow loads, live loads, tension stress... that kind of thing...

Keep in mind that the physics engine is not designed to be that accurate. Its more of a game physics engine. Maybe you could do a first approximation of stresses and what not. But I think you would need a real engineering software for anything meaningful.

@unknownuser said:

I tested something last night with it... I took the bricks in the terrain test file, and shrunk them down to about the size of a small rock... then copied them over an over and over until there were hundreds and hundreds of them in a cluster hanging in the air waiting on me to drop em... I wanted them to fall all at once and seem to be a fluid pour of small objects... but what I got was a few dropping at a time... by OC'd E4300 couldn't handle it...

This plug-in hasn't been optimized yet and lots of objects will go slow. I expect I can at least double the performance on >100 objects without too much effort.

But the biggest bottle neck is sketchups performance. It was not really designed for moving hundereds of objects dozens of times per second.

Part of your problem may be that you shrank the objects too much. There is an upper and a lower limit to how big and object can be. Objects that are too small wont move.

Chris

Thanks everyone! Here are a few answers to the questions.

@unknownuser said:

oh yeah with this ruby you can make a model of our solar system, and then have collisions...

Yes.

@unknownuser said:

you can have a car driving down the road...

Yes. In fact I hooked up joystick support a while back. Ill expose it in a future version.

@unknownuser said:

@unknownuser said:

a back hoe digging...

Doubt it. Deforming terrain isnt possible with this plugin.

@unknownuser said:

now can I export movies of this?

Not yet. I do have a separate plugin called SketchyReplay that records and plays back animations.

@unknownuser said:

is there wind and water effects?

Wind no. Water possible in a future version.

@unknownuser said:

can I assign weight to an object, like a brick, and a 2x4 and a concrete pad, and then weigh the whole structure?

The physics engine supports materials. A future version will expose them. I dunno about weighing a structure. It might work.

Thanks! What do you mean by "dual install"?

Its still got lots of missing features and bugs but here we go!

Google Code Archive - Long-term storage for Google Code Project Hosting.

(code.google.com)

The docs are very much a work in progress.

Chris

You need to make the "blade" out of a bunch of boxes. Here is an example by Google Guy from 3dwarehouse:

http://sketchup.google.com/3dwarehouse/details?mid=d601b738003b932aedcfef0daa99bceb&prevstart=60

spiral box-mover.skp

No way in current version to preselect the object. Thats a good idea tho.

You can double click on an object to have the camera point at an object. Ctrl + double click will cause the camera to also follow the object.