Posts made by DanYHKim

I created a video that shows some characteristics of jointed solids in SketchUp/Sketchyphysics.

http://www.youtube.com/watch?v=74ji-NXsdDI

Is there any way to change the properties of many different joints at once? For instance, I have dozens of motors that I would like to have under the control of one slider. Rather than adjusting each one in the 'Inspector', I would like to be able to change all of their settings at once. It would also be nice if I could assign them all to the same slider control in a single action as well.

Can this be done? I'd even be OK with a script to generate a batch of motors or something.

Thank you so much! That's exactly what I needed!

A few years ago, I recall reading about a type of joint controller that gives a reciprocating motion to a piston. It was enabled by replacing the "slider('slidername')" with "reciprocator(some_rate_nuimber)", or something like that.

Does anyone know what this was called? I cannot remember at all.

Also, are there any other kinds of joint controllers that can be used? For instance, I have a set of motors that I intend to run at a constant speed. I don't want to control their speed during the simulation. Can I give them a joint controller that won't show up in the control panel?

Some of the more complex and subtle aspects of Sketchyphysics are not well documented. I'd love to see ore information on such scripting commands as 'on touch' or 'do this when all of these doors are open' or something like that.

Paul: These are beautifully done!

I was teaching a lab section in which I needed electrical floorplan symbols, and could not find any for SketchUp, so I made some up. They are in a <a href="http://sketchup.google.com/3dwarehouse/search?uq=0653493766545200612055374&styp=c">collection at the 3D warehouse</a>. I also made ones for planning plumbing, 2D doors and windows, etc.

One thing you might consider doing, since you are creating groups that include 3D and 2D elements, is to place the different classes of objects into different layers. Put the actual electrical 3D fixtures in a '3D_electric' layer, the horizontal 2D symbols in a '2D_horizontal' layer and the 2D vertical symbols in a '2D_vertical' layer. Then, you can change their visibility globally in your model.

Thanks MPTAK! I never knew you could define track and follow in a scene description like that. By putting a 'follow' object on a piston, you can have a camera traverse like a 'dolly' shot. I've always tried doing this by starting the simulation, then assigning track and follow by right-clicking, but this is really much better.

Well, there is a quick answer to the question of Joint scale: The joints are assigned to a layer that can be hidden with no ill effects. Just turn off the visibility for the SketchyPhysics Joints layer.

Getting back to the initial question: You're trying to make a trestle table base using rectangles that are of the same width?

If I am not misunderstanding things, I would figure that I would:

1. Make a single rectangle to represent one leg. Make it extra long.
2. Make this rectangle into a group
3. Use my Rotate tool to rotate this rectangle group about its center
   1. Press the CTRL key to make this a Rotate-Copy action
   2. Rotate the copy of the rectangle to the desired angle
   3. Do this again for the opposite leg
4. Edit the rectangle groups
   1. Adjust their lengths
   2. Trim the angled ones so they are flat and horizontal on top and bottom
   3. Push/Pull them to make them 3D

This would be a useful classroom exercise that demonstrates:

1. Isolation of geometries using groups
2. Use of Rotate tool and use of CTRL to modify a Rotate into a Copy/Rotate action
3. Editing within a Group
4. External Guidelines to guide editing in a group

(sorry, I'm too lazy to learn how to do list formatting)

@cmartin said:

@dave r said:

Ah. I see. So what's the situation on using plugins? Fredo's FredoScale plugin has a very helpful tool for making the diagonal legs. if the exact width of the legs is important.

I can install some, but I have to have our tech install them. I'm not allowed to do it. And then, if a computer needs to be reimaged, usually they need to be reinstalled. So, anything that I can do with the regular tools easily, i would rather do it that way if possible. That said, I do use some tools. We use the lines to cylinder tools when we do our park project. If it really can't be done easily without tools, I will use them.

I have a similar problem. I do not have admin rights on the lab computers, and so cannot install plugins. It turns out, if the lab computers have SketchUp installed, you can run a different instance of SketchUp from a USB drive.

On my home computer, I install SketchUp, plugins, components and materials bonus packs and other stuff that I want. After installation, I copy the "Google SketchUp 8" folder onto my flash drive. I also copy the Preferences.dat file that I generated when I created custom keyboard shortcuts, since I like having my shortcuts with me, but they do not get transferred automatically.

On the lab computer, I can run Sketchup.exe from the flash drive, and I have my plugins and components libraries available to me. I think this only works if my USB Flash version of SketchUp is a good match for the version already installed on the lab computer. Still, it works pretty well. It can be a little slow for some functions, because the computer is accessing the USB drive for the program, instead of the hard drive, but I can live with it. I think, if you do not have Admin rights, you can still copy your customized SketchUp program folder onto the computer desktop or some other location where you have access, then run the Sketchup.exe file from there, or even create a shortcut to the alternate location.

I made a video showing how I do this. It is a boring video, and I don't really get to the meat of the matter until 5:40. I seem to be the only one who does this. If it works for you, please report it on this thread. Thanks

[flash=425,344:3feltu5m]https://www.youtube.com/v/0VQmkz-MraA[/flash:3feltu5m]

Making a complex object in SketchUp is an exercise in breaking the object into simple geometries. Having used SketchUp for a while, I have grown used to looking at something that I wish to model, and parsing it into component geometric primitives. For instance, a coffee cup is a cylinder with a tube attached to it. The cylinder is offset by a small amount, and the inner circle is pushed almost to the bottom. A separate bent tube is made using the FollowMe tool along a profile made from a few lines and a radius. These are positioned together and intersected, then the extraneous bits are deleted.

I now have a habit of seeing furniture, utensils and buildings as a set of geometric solids and their modifications. This makes the world look kind of strange (Does anyone else have this problem? Do I need medication?).

The scifi buildings can also be seen as a collection of constituent parts that are positioned, duplicated and stacked together. Be sure to make these constituents into groups or components before placing them on each other.

In part, the cylinder solids of your piston are just for show. They do not really contribute to the mechanism, but they do complicate the model. I'd suggest that you remove them until you have the simulation working properly.

I looked at your model, and still don't know how it is supposed to work.

When I run the simulation, the cylinders kind of explode. They occupy the same space, and so they push apart when the simulation starts. I think you may need to set the cylinder properties to "no collision" so they don't interfere with each other in this way.

The door is attached to a hinge. I assume you intend the door to swing down from its upright position around its bottom axis.

I am not sure what the piston is supposed to do. As a guess, you intend the door to work by having the piston somehow push an object against the door and make it swing down. Am I correct?

---

OK, maybe I'm wrong. Are you trying to make a door that opens kind of like a garage door? That is, the door lifts up, but also its top edge slides horizontally until it is fully open and horizontal? If so, then maybe you should replicate the mechanism of an actual automatic garage door opener.

I use SketchyPhysics to do this in a roundabout way, but it does not export. I use CamStudio to capture screen activity into an .avi video, but do not export from SketchUp.

Check the logo animation I prepared for a Project Lead the Way website:
http://pltw.nmsu.edu/cPage.aspx?pageid=main&queryid=aboutlogo

Your model might be made to move using SketchyPhysics, controlling the door hinges with an oscillating control, so they open and close repeatedly. Then change your camera POV using Orbit or by controlling the camera by having it "follow" and "track" a hidden object under control of a servo joint.

This is a rather complex set of controls, though, and tricky to implement. If you expect to do this kind of thing often, then it may be worthwhile to learn how to do it. Otherwise, you might be better off using one of the other suggestions in this thread.

Actually, if the open/close action does not have to be concurrent with the camera movement, a more simple series of actions can be recorded using CamStudio and then cut into a single sequence using some video editing software.

The car that you downloaded was not originally designed for use with SketchyPhysics. You correctly isolated the wheels from the chassis, letting the wheels be attached to motors, but the motors are themselves static objects, I think. If you place a motor in a SketchUp model, then join it to a wheel, the motor will stay in one place while making the wheel turn in the air.

I think you may have some progress if you first edit the car chassis group, then place motors inside the group, then close the group. This will make the motors static within the chassis group itself, but not static within the model. Then, join the wheels to their motors. The motors will turn the wheels, which will propel the rest of the car.

Um, there are extra details for the servos that let you steer the car, but I am too lazy to describe them here. I do recommend that you actually use only one motor, as is normal for a car. The motor can be placed in the midpoint between two driving wheels (the rear wheels, perhaps?). Then, when you join the motor to the two rear wheels, they will both turn in synchronization. They will not, however, behave like car wheels with a differential gear. Still, it will be good enough to play with. The front wheels can be joined to the steering assembly using passive hinges. If you use two servos to control the turning of the front wheels, they can be linked to a single named controller, so they will both turn in synchronization. This will reduce the number of controllers to two: one to control the motor speed and one to control both servos.

I have often used SketchyPhysics for complex machine simulations and animation. I use either CamStudio or Camtasia for screen captures during the simulation, to capture the action. Using SketchyPhysics can be a challenge, especially since the machine simulation requires duplication of the actual components and their jointing, which is not always straightforward. The results can be very gratifying, though.

Here is a link to a video showing a mechanical chile pepper cleaner. The machine itself and the closing logo animation were made using Sketchyphysics.
http://www.youtube.com/watch?v=YRNFi0DzGm4

The animated logo I use for NMSU-Project Lead the Way is also a SketchyPhysics animation sequence
http://pltw.nmsu.edu/cPage.aspx?pageid=main&queryid=aboutlogo

For a short animated sequence, one could use one of the animation plugins described in this thread, or even simply re-position the different objects and take a series of screenshots or 2D exports to put into a stop-motion animation sequence.

I am not familiar with how Solidworks does animation, but I once made a moving toy train engine (rotating wheels, moving along a track) using Inventor. I was not impressed with the method described to me for Inventor to animate that action, since it seemed to use a change of angle over time script to make the wheels rotate while simultaneously changing the train's position over time. It seemed like a cheat to me, since the wheel rotation did not 'drive' the movement of the train, but was only synchronized to be proportional to the x-offset over time. In any case, the train still needed to be constructed in a functional way, with jointed constraints to keep all of the components in proper relation during the movement, just like in a SketchyPhysics simulation.

I have been using layers to separate different conceptual parts of a house plan. In part, this was done to help me go from a floorplan sketch on paper to a SketchUp model.

See this page: http://et365.pbworks.com/w/page/46205883/11%20Use%20Layers%20to%20Organize

Wow, ambitious! Still, it's good to have a challenging goal.
You should learn the basics first, of course, before trying something really complex. If you wish to model mecha, do you intend for them to be functionally detailed, or just correctly shaped? For instance, two arm components may be placed together in a way that makes their geometries overlap, but they are not actually 'jointed' in any way that would reflect their structure in a real construct.

There is a channel on YouTube for SketchUp for Dummies (yes, the book) that has many good video tutorials. I'd start there, and work through creating everyday objects to get a handle on the program.

For the future, you might look into Sketchyphysics to make a moving mech.

By pressing the shift key while dragging, an object may be dragged in the 'upward' direction. Releasing the shift key restores horizontal dragging while the object is suspended above the ground.

Ha Ha. Doing this reminds me of the animated version of "Flatland", in which one character tries to tell the others about "up". The others just say "You mean 'north', don't you?"

I have used it to create animations and simulations of engineering projects built by others in my department

[flash=600,410:1m4yup38]http://www.youtube.com/v/ZUL6S5JMxls[/flash:1m4yup38]

The videos are produced as part of progress reports to partners and clients, and the models and animations help to illustrate functions that are difficult to see in real life, or which may be dangerous to film on-site.

Braaaaiiinnnnsss!

[flash=640,480:1hwi95zr]http://www.youtube.com/v/L0ZNFJFcRqI[/flash:1hwi95zr]

This is a SketchUp model of the http://youtu.be/rA3mNjis3m4 LONI Probabilistic Brain Atlas (LPBA40) that I made by importing the 3D brain regions from the http://scalablebrainatlas.incf.org Scalable Brain Atlas. Each of the paired structures is in its own layer for visibility control and automatic coloration.