Algodoo

Nice Demo.

Regarding,
"One script makes a circle slowly move to the right at exactly the same rate as the texture, so that it appears like the texture is not moving in that circle."

On my PC it is close to the same rate, but not exact. Also it only works for simulation frequency value = 60.

This is what I did to make it exact and frequency independent:

1. Set all _counts = 0.0
2. Replace pos = {[1.8 + (sim.time / 20) % 3, 4.2]}
with pos = {[1.8 - _count, 4.2]}
3. (Optional) Replace textureMatrix = {[1.0, 0.0, _count + pos(0), 0.0, 1.0, pos(1), 0.0, 0.0, 1.0]}
with textureMatrix = {[1.0, 0.0, 1.8, 0.0, 1.0, 4.2, 0.0, 0.0, 1.0]}

I agree. A simpler fix would be to replace the word "exactly" with "almost".

Answers:

1. V is a local variable whose scope does not go beyond the onLaserHit event. The console does not see local variables.

2. The input circle has 2 axles; 1 stretched and 1 normal. The normal axle (motor widget) controls the RPM. The stretched axle connects the motor (input circle) to the transmission. Scene.my.inputRPM is an output variable for converting actual angular velocity in rad/sec to RPM.

3. No.

Xray, Yes. Lethalsquirl, Thanks.

Nicely done.

Congratulations on the first toolbar scene.

You may have not understood the question. The question is:

How does Algodoo calculate the coefficient of friction when the coefficient of one material is different from the other?

For example, if the block has µ = 0.123 and the tray has µ = 0.456, then how does Algodoo calculate the combined COF (0.237)?

Also, in your statement above, theta should be the angle from the horizontal, not vertical.

Better results. Simpler approach. I like it.

I think you totally missed the boat. Your latest statement is equivalent to your first statement. Although both statements are true, I don't believe either answers the question. I would think the formula would be in the form of:

u = f(u1,u2)

where

u = combined coefficient of friction
u1 = COF of one material
u2 = COF of other material

Awesome.

Also awesome. It's amazing that a car that old is so cool.

I figured that nobody would get it. That is why I offered such a large prize. I'll end the contest now, just in case somebody does figure it out.

TheInventor,

Yes, I did come up with this on my own. I think I searched transmission scenes first, but I know I didn't check car scenes. Seeing that your car scenes were made after this scene, I suspect we both came up with the same idea. I wouldn't be surprised if someone else came up with the idea first.

Excellent. Best answers so far.

On car 7 you can identify the thruster by using the box tool to select the car and wheels and then choosing Selection>Select to identify the component you would not expect to be part of the car.

Solutions by car number:
1. Tiny fixjoint fixes car body to background.
2. Car body glued to background.
3. Two tiny axles hold the body to the background.
4. Sky colored circle glued to background in front of car. Zero wheel friction.
5. The car is up on two sky colored J layer blocks. J layer is turned off.
6. Braked and depied original wheels. Added zero friction, slightly smaller wheels over original wheels.
7. Car forced up against two sky colored J layer glued to background circles by tiny thruster. Zero wheel friction.
8. Thin spring attaches rear of car to background. Zero wheel friction.

I guess so. You snooze you lose.

I disagree, you still are one of the best thyme scripters. At any rate, don't feel too bad since the scene was intended to be a puzzle and not a contest. You were the first to call it a contest and I figured that was my big chance to make a snide remark.

P.S. Just to be clear, I do agree that you are one of the best engineers in Algodoo.

Nicely done. I like the close tolerances and smooth operation.

Xray,

One interesting observation: If no center wheel, a balanced load, and rotating wheels, then the vehicle has very low friction and will slide down a slight incline.

This scene looks great and works quite well. The scene is fine without any changes, but I have some suggestions:

1. The indexer has (4) large blue wheels; (2) left and (2) right. The left pair are comprised of (1) driver and (1) driven and are connected by (1) connecting rod. (3) equally spaced connecting rods connecting the left pair would work better. The (2) additional connecting rods can have no collision layer. The reason for the additional connecting rods is to push the driven wheel when one connecting rod is at top dead center. You can also get by with just (2) connecting rods if the second connecting rod is 90 degrees out of phase with the first. The discussion for the left pair also applies to the right pair.

2. The indexer works like a rack and pinion. If you turn off all layers except for layer A and run the scene you will see the fit between the rack and shifting forks is quite tight. If the shifting forks are replaced with frictionless circles and the rack has some lead in angles cut into it, then the movement will be much smoother and the scene will run at 60 to 1200 Hz.

3. The flux capacitor that is set at 3 needs to be set to 7 for better performance.

Nice scene. Well done.

This is what I did to get it to work:

1. Reboot computer.
2. Reformat hard drive.
3. Set phlogiston generator to 3.1.
4. Delete the flux capacitor.
5. Springs 4N/m
6. Use (2) additional sky hooks.

Thanks for the feedback. The device does not tolerate higher speeds well. The lower restitution helps somewhat. I traced the mechanism so it is not too accurate. Maybe if I made a super precision one from scratch it would work better. I don't think that's going to happen however.

Elegant.

My favorite is the horse and cart.

Xray - That thought crossed my mind, but the expanding circles are on top of each other so I used collision layer 0. Since I did that, I couldn't think of an easy way for an observer to detect the frequency. Then I figured take the easy way out and post the "Doppler Effect" hyperlink in the description. Feel free to change or embellish the scene as desired.

Good idea. Looks like you are the first to come up with it. This method should come in handy for making a new type of ragdoll.

I'm curious as to how you added the texture to the Deformable Material. My best guess is that you added script to the update event in each box to change the textureMatrix and then deleted the code after running it.

I give this a 10 because it's done well and helps people out. I've seen many scenes with stretched hinges, but I believe this is the first tutorial. The only thing I would suggest you add is to describe a method of selecting one of the unstretched hinges below the stretched hinge.

Thanks. I did not realize that since I failed to search phunbox1 before doing this one.

This is what I did:
1. Select all boxes in deformable material.
2. Insert the following in the update event:
G1 = 0.4;
G2 = 0.5;
D1 = 0.3;
D2 = 0.4;
textureMatrix = [G1 * cos(angle), -1.0 * G1 * sin(angle), G1 * pos(0) + D1, G2 * sin(angle), G2 * cos(angle), G2 * pos(1) + D2, 0.0, 0.0, 1.0]
3. Remove the code in the update event.