SketchyPhysics 3.5.6 (26 January 2015)

platinius · 9 Sept 2014, 11:10

Can you show an example, I can't reproduce this.

I'm sorry about that, it seems I didn't try enough. There is no difference between the axes. It irritated me that the moving direction of a piston or slider is opposite to the direction I choose with the mouse when positioning. For example, if I put a slider joint on the corner of a box and drag the mouse to the positive green direction it will move only to the negative direction.

@unknownuser said:

I can't change it because it could break compatibility with prior models, but I can make it to evaluate everything in the control box. For example, if you write 100mm it will turn it to 3.93.

Maybe this would help a little bit. To put the units besides the input boxes would be great and help people also. Maybe you know that a Mars orbiter crashed in 1999 due to falsely used units. I assume no one uses SP to constructed actually flying space ships, still it feels good to know what units one uses.

I found this thread which gives some information about units in SP:
http://sketchucation.com/forums/viewtopic.php?f=61%26amp;t=53209

A world scale factor of 1.0 and gravity of 9.81 (m/s²) seems to be suitable if using metric units.

Maybe this thread is of interest for you also. Looks like SP's author asked this question:
http://newtondynamics.com/forum/viewtopic.php?f=9%26amp;t=4684

Anton_S · 9 Sept 2014, 16:10

To make the mouse control desired, simply multiply the whole controller by a negative sign.

I will add a list-box from which you could choose the type of limits angle/length.

Anton_S · 9 Sept 2014, 16:31

@cotty said:

A new version is out and the changelog says: "Fixing up SketchPhysics export" (not tested).

Cheers!

It exports without problems, although the error comes when try to run the exported animation in Indigo render 3.6.28. Maybe I should download Indigo 3.8.x which is not available yet?

cotty · 9 Sept 2014, 17:59

@anton_s said:

Maybe I should download Indigo 3.8.x which is not available yet?

You'll find the newest beta in the forum: http://www.indigorenderer.com/forum/viewtopic.php?f=1%26amp;t=13252

Trobius · 6 Oct 2014, 23:35

Hi there! I've been an on and off user of sketchyphysics since 2.0.

Would it be possible to create a way to get an emitted object's lifetime? I know about the setLifetime function, but is there a similar "getLifetime?"

Anton_S · 7 Oct 2014, 14:19

Hello, William!

Yes, SP doesn't have these methods. The API is quite incomplete.
I just added getLifetime, getLifeStart, and getLifeEnd.

Is there any other getter or setter functions you think shall be added before I post an update? Sorry, I can't think of any myself.

ashscott · 8 Oct 2014, 03:15

You're a champ Anton, your efforts are very much appreciated.

Wish I had time to get back to some of the SP work I was doing earlier.

If anyone wants SP inspiration, check this model out: https://3dwarehouse.sketchup.com/model.html?id=5b618d4ba6c22ca85fd35d52fb19ea9b

In fact, all of Phonic's work is pretty amazing: https://3dwarehouse.sketchup.com/user.html?id=0127263341868366760323686

Anton_S · 8 Oct 2014, 06:53

Thanks, Ash.

Lately, I haven't created any SP either. I suppose, that is because I kinda lost passion in it.

Phoenix is a good SP modeler. He's sharing some great stuff!

Mr.K made some amazing things too. For instance, take a look at the Blue vs Red. You control the bot to get across the puzzle. It may appear mind boggling at first, but you'll get it mastered after some experience.

ashscott · 8 Oct 2014, 08:01

Have you had any interaction with Phonic? I couldn't get a response when I tried some years ago - I wondered if he was only mandarin speaking.

Anton_S · 9 Oct 2014, 06:46

@ashscott said:

Have you had any interaction with Phonic? I couldn't get a response when I tried some years ago - I wondered if he was only mandarin speaking.

Nope, I haven't. I doubt that Phoenix even reads the comments. Usually people respond to their comments by updating the model description with responses, but I never seen him do that.

ashscott · 10 Oct 2014, 01:19

One thing with Sketchyphysics I did wonder about - and I have no idea how to execute it - would be a "Cut" function. I have modeled saw milling machinery with SP in the past but always had to do some variation of a breakable joint to simulate cutting - due to the physical reactions in breaking a joint, you can understand that it wasn't pretty.

Any idea how to cut an object so that it becomes two?

Anton_S · 10 Oct 2014, 02:45

Piece of cake!

Copy this piece of code into the scripted field of the body that you want to be cut:


onTouch {
  split(self, 2)
}

What happens is that it splits when it is touched by another body. Increasing the value will create more cuts.

Of course, the code may be changed to have the body be split in another occasion, for instance when it touches a particular body, or at specified frame... If you provide some instructions I could easily write you a code.

Here is a little example:cut_body_example.skp

ashscott · 10 Oct 2014, 03:10

Very cool!

I think I've seen some reference to this before.

How would I control the cut so it occurs in a specific place?

For example, on a piece of wood - to only be cut where the saw touches it?

Ash

Anton_S · 10 Oct 2014, 08:46

SP doesn't have this method, but I created my own.
https://3dwarehouse.sketchup.com/model.html?id=ua22b41f2-9654-4d70-898b-46d96e687272

ashscott · 10 Oct 2014, 09:54

Anton,

I am stunned

I have tried so long to get a working function like what you've shown and have failed miserably - this is totally amazing. I hope you don't mind me pillaging your code for ideas?

Frenchy:
@unknownuser said:

And also the white cross texture box "transparent" who is drawn

For some reason "Hidden Geometry" is getting turned on when I run an simulation the first time. Go >View>Hidden Geometry to turn it off.

pilou · 10 Oct 2014, 12:50

Cool function!
But seems there is a glitch!

When I use these 2 menus!
After the Record Animation, replay etc...
Animation is stopped at the moment of the box must be "exploded" on the inclined plane!
Can you verify this ?

And also the white cross texture box "transparent" who is drawn!
This is the image of the result wished!

cut_body_example_glitch.skp

pilou · 10 Oct 2014, 12:55

Thx

Anton_S · 10 Oct 2014, 16:26

@unknownuser said:

When I use these 2 menus!
After the Record Animation, replay etc...
Animation is stopped at the moment of the box must be "exploded" on the inclined plane!
Can you verify this ?

The animation doesn't handle added and removed objects during simulation.

What happens behind the scenes:
When the body is about to be split, the body itself doesn't split, but rather two other bodies are added in similar form. The original body becomes hidden and set static, meanwhile the two added bodies take over the scene. When simulation resets the original body is unhidden, and the added split bodies are deleted. The animation tool is not complex. It does not record added and removed bodies during simulation.

Anton_S · 10 Oct 2014, 16:30

@ashscott said:

Anton,

I am stunned

I have tried so long to get a working function like what you've shown and have failed miserably - this is totally amazing. I hope you don't mind me pillaging your code for ideas?

Thanks! I'd be impressed to see someone use my code

pilou · 10 Oct 2014, 17:23

@unknownuser said:

It does not record added and removed bodies during simulation.

Ok!
So, how do save the result of the normal result if you want to use it for something?
For example I want use the brocken rocks for an exposition!
Now as soon has i want select them (broken rocks) the animation restart at the beginning!

In the past I was making that without problem!