SketchyPhysics3.2 (Dec 2)

[bossdave]

I am running SU8 with wine on Ubuntu with SP3.2. The UI box appears showing: Joint, State, Properties, Shapes , but no details. Same problem withSP3.1. Any ideas what I am missing? Thanks

[phy]

I am running SU8 with wine on Ubuntu with SP3.2. The UI box appears showing: Joint, State, Properties, Shapes , but no details. Same problem withSP3.1. Any ideas what I am missing? Thanks

There you go http://forums.sketchucation.com/viewtopic.php?f=61&t=33030
webdialogs don't work in wine without this tweak.

[CPhillips]

- New script command setFrameRate overrides physics settings framerate.


Hello, trying to implement the set frame rate command to get the model to slow down on faster computers so we can anticipate the results.

Can you let me know the usage and where to put it.

I've tried setFrameRate=5; in the on tick section and it doesn't seem to make any difference.

Thanks,

Joe

Thats not quite how it works. a frame rate of 5 will make the physics simulation step 5 times before updating the sketchup model. To make it go a little slower you could use a frame rate of 1.

[robint]

help UI window not working

Postby robint on Mon Jan 03, 2011 8:59 am
ive got su8 latest and sp 3.2 installed

when I try to inspect joints i get the usual info for a hinge (say). when I try to input say accel or a controller name , it accepts them but doesnt do anything - no slider in the run panel

Ive tried the other tip of clicking on the UI button to exit the UI window to no avail

I saw a tuorial where it said that you can turn a hinge into a reversible motor by putting accel = 1 and giving the controller a name - which is then supposed to bring up a slider in the run panel - i just get a blank.

then i go back and look again and just get blank boxes. only restarting su8 will clear the prob but it comes back if I try to change a parameter

cheers Robin

ps I havent got so excited since I first used SU4 - this could be a wonderful educational tool if physical values could be added to demonstrate newtons laws for example

I made a double pendulum the other day, but as already said, there's lots of real world physical attributes to be addressed (eg mass, density, friction, elasticity etc) but its early days

[robint]

Hi guys

how or where do I post a skp model for discussion

also i cant post a link here?

robin

[robint]

This site seems to be moribund, not a lot happening?

Anyway Ive solved the UI problem

so all working ok now

[robint]

here my 2c worth for sp 3.2

if you want to make a reversible motor joint, use the hinge (as per sp2) and set the controller blue box to

quote slider ( 'anyname' )

you can see the same construction using the motor joint

wish I didnt have to waste hours getting to this point.

Also

to make magnetic solids work you need to set the ui box status to magnetic
and the magnetic force to a large value eg +- 1000

not obvious is it?

I wonder whether its worth contributing to a wikimanual at5 this stage if thereis going to be an sp4 completely recoded?

Robin

[jblively]

to make magnetic solids work you need to set the ui box status to magnetic
and the magnetic force to a large value eg +- 1000

I do believe that magnetic force is also affected by mass and scale. So if the model is very large, you'll need a larger value for magnetic force. If you have a small scale model, you can use a magnetic force of as little as 10 to see results.

There is so much involved in SP, more documentation would be nice, but i'm just glad we have people here we can chat with who want to help!

[Pilou]

Does this vervion can works on the V6?

[robint]

Hi JB

good point

afik though there is a density coeff, I dont know how well it correlates to the mass of an object?
the apparent mass i governed by the size of the collision shape as set in the rt click physics setting

havent figured this tiresome details out yet

I have a number of cu4rious physical models i would like to post for discussion (eg double pendulums etc) but havent yet found a way to post these little experiments.

It seems daft that one cant attach these on this forum - severly limiting

Any ideas?

[CPhillips]

Yes magnets are effected by the size of an object.

You can attach files to posts. Look at the bottom of the form and there is an "Upload Attachment" tab.

[robint]

hi all

sorry pardon didnt see the tab for uploading


I was trying to make a chain rotating around 2 sprockets. The chain seems to want to fly apart, its all chaotic? even though its all supposed to be stationary, any ideas

btw i have su8 and sp3.2 dec2010

its all good fun but i wish i had more control over the way things work, bit hit and miss at the moment

btw although bugsplat is a good tool, i dont connect my main machine directly to the net for obvious security reasons, so cannot utilise bs directly. It would be much more convenient if bs made a composite text file stored conveniently which i could gather up and post here to help with su crashes. Its a bit cumbersome at the moment

cheers robin

[TIG]

CPhillips
Please see here for an 'issue' with group.definition viewtopic.php?p=300105#p300105

[robint]

hi CP

thanx for the tip, will see if i can make it so.

any pointers on where to start on Ruby so i can at least know something of what im doing?

cheers

Robint

[robint]

CPhillips
Please see here for an 'issue' with group.definition viewtopic.php?p=300105#p300105

Hi
I tried the code but it seemed to make things worse


Code: Select all
class Sketchup::Group
if not Sketchup::Group.method_defined?(:definition)
def definition() # make it so you can use group.definition
return(self.entities.parent)
end
end#if
end


something about a chain sp doesnt like

Im stuck, my chain flies apart

robin

[robint]

High CP

I have used Poser 5 in the past and learnt about inverse kinematics and joints

I think there is a fundamental limitation that prevents you making a chain of joints because the last child joint has to join the first parent so the parent must then become a child. This would be inherently unstable (like positive feedback) which is why the joint flies apart in pieces

Can anyone confirm my guesswork or poiont me somewhere that a working chain has been made (ie will revolve around a sprocket

cheers robin

[hpnisse]

Hey, robint!

Your chain works perfect when you set the collision state correct in every single object

Re. my chain 1.skp

[Oxer]

Hi,
I have installed SketchyPhisics 3.2 on Mac with OSX 10.6.6 and SU8 and the plugin don't woks, SU read the plugin, appear the toolbars, you can create the shapes but when you press the play appears a window with this message:
Error initializing the Simulation: : uninitialized constant MSketchyPhysics3::SP3xSimulationContext::SPSounds /Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/ControllerCommands.rb:777:in `initialize'
And in the ruby console this:
String doesn't compile: uninitialized constant MSketchyPhysics3::SP3xSimulationContext::SPSounds#<NameError: uninitialized constant MSketchyPhysics3::SP3xSimulationContext::SPSounds>
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/ControllerCommands.rb:777:in `initialize'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:727:in `new'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:727:in `initialize'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:1623:in `new'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:1623:in `startphysics'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:1650:in `physicsTogglePlay'
/Users/Oxer/Library/Application Support/Google SketchUp 8/SketchUp/Plugins/SketchyPhysics3/sketchyphysicstool.rb:1738

I have reinstalled SketchyPhysics3.1 and works.

[robint]

Hey, robint!

Your chain works perfect when you set the collision state correct in every single object

Re. my chain 1.skp

Hi H

Thanks for that tip, the model chain works for me now, but I dont understand how setting the object state to "show collision geometry" makes such a radicle difference?

obviously i dont understand this state? I looked on the tutor manual but that wasnt helpful
so i am puzzled

nice that one can actually make a set of revolving links

What we need now is a workable spring (with variable rate and damping). the legacy one only works in sp2.3 not in 3.2. perhaps its work in progress

can anyone tell me if joints have a built in friction?

A simple pendulum will slowly come to rest, so there must be some restraint or energy loss built in? is this variable?

in mechanical systems you need mass, stored energy (spring) and friction (damping) preferably using SI units so as to start physical modelling

BTW I was once involved with a brilliant guy who made an amazing music generating prog that allowed exploration of scales, rhythms etc. BUT he was a C++ script magician and his prog became a tangle compost heap of widgets with a poor and almost unusable manual. I tried to help sort out the mess but the guy simply couldnt organise his thoughts in a consistant and methodical manner so his brialliant concepts came to nought as prospective users lost enthusiasm and gave up.

If anyone is preparing to organise a proper manual for SP4 then I can offer my 2c worth


cheers

Robin

All good stuff as I had come to a brick wall till now

[robint]

hi all

Im posting some models that illustrate some points and queries

all comments gratefully received

Robin

[solodown]

Toujours pas de nouvelles pour faire fonctionner ce plug-in sous Mac OS X 10.5.8 avec Google SketchUp ?

[zunkian]

Hi!

Is there a manual for SketchyPhysics for beginners?
If there is one, please upload.
Thank you.

Andy

[dereeei]

Indeed a user manual for users that did not used ketchyPhysics before would be nice. I noticed that some beginners tips are to be fond here http://sketchyphysics.wikia.com/wiki/SketchyPhysicsWiki , but I'm sure that version 3.2 have much-much more features than are detailed there.
Thanks.

[4dHans]

Could you do like explosions in a future version? That would be cool!

[mickeyao]

MBP with 10.5.8 Thanks!

[sketchyKev]

hi all

Im posting some models that illustrate some points and queries

all comments gratefully received

Robin

For the first one (rotating cone) you can make the motor reversible by changing the controller code to (slider('motor8055')-0.5)*2

Using that code the middle position of the slide control is off, full left turns one way and right turns the other way.

For the second one, to create a lift capsule do this:

Create a solid floor.
Place a wheel capsule with built in hinge on the floor.
Place a lift capsule with built in slider on the floor.
Using the JCT click on the hinge joint, then ctrl-click on the slider.
A menu pops up asking if you want to "Create a worm gear..". Click "OK".
Run the simulation and turn the hinge capsule clockwise and the other capsule should rise.

You can build a lift from scratch from components. Just make sure each joint is grouped with the moving objects and joint connected with something static before trying to make the worm gear connection.

For the record a slider is not a piston with the accel and drag values set to zero. A piston with those values will not move.

For the rotating box using a slide controller on a hinge, the program does not recognise a controller called "speed" so it has defaulted to servo behaviour. You can get the same behaviour from a servo by setting min=-180 and max=180. It is known that servos behave badly if you try to get them to complete full circles or more than one circle. There is no need to mess with the hinge controllers as servos and motors are provided.

For the box on a spring, the spring is orientated vertically and does not allow sideways movement or rotation. When you try to drag the box the drag action defaults to horizontal movement. To pull the box up or down inline with the spring you need to hold left-shift on your keyboard while dragging with the left mouse button. Try the spring orientated sideways and it should work fine. The springs are on the stiff side so it is worth playing with the accel and damp settings.

Hope that helps.

[Alainbo]

There are months now that sketchyphysics 3.2 installs 3.1 !!!

Don't understand this update !?

[bouleaux]

Hello,
congratulations for this marvellous job !
I'm using sketchup 8 on a Mac Book Pro running on Mac Os 10.5.8
and I would loooove to be able to use sketchyphysics with this computer
any chance ?
thx again

[Oxer]

Hello,
congratulations for this marvellous job !
I'm using sketchup 8 on a Mac Book Pro running on Mac Os 10.5.8
and I would loooove to be able to use sketchyphysics with this computer
any chance ?
thx again

Hi, bouleaux
I'm a mac user too, the last version 3.2 doesn't work on Mac but the 3.1 version works fine on OSX Leopard with SU 8.
I hope this help you.

[bouleaux]

Hello Oxer, many thanks
I tried to find the 3.1 version, but it doesn't seem to be available for download anymore (on this page : http://code.google.com/p/sketchyphysics/downloads/list)
Do you know of another place to find it ?
Thank again for your answer