Units of Measurement in Sketchyphysics
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Good day,
I've been working for a project at university trying to use sketchyphysics as a means of drawing conclusions, by solving real problems in a simulation. So far, I have maneged to make some models, but It's been hard to me since I don't know what units of measurement I'm using when I type them in the UI console, like the damp or the acceleration in joints, or the strenght of magnets, thrusters, and breaking forces of fixed joints. The parameters of the buoyancy settings are also a mistery to me, like the current on XYZ axis or the viscosity. I really need to know what units am I using, if anyone knows about it, or knows where I can get this information, please let me know.
thank you!
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Thoughtful question which I presume eventually may need to be done empirically. I will dig around for the post but essentially from memory and model forensics the following settings will at least model gravity correctly. When you get into other matters I think that the effects of similitude might start to complicate things but it is still worth the effort. If your model is modeled in meters you can best model "reality" by the following settings:
framerate: 2
gravity: 9.8
worldscale: 1velocities are then set in ruby code with the following formula to account for the inch/meter ratio and the frame rate.
if v is your desired velocity in meters per second...
input_velocity = v * 39.28/2
The best way to test this at least in terms of rule of thumb is to raise a ball to 45 meters and see if it takes 3 seconds (180 frames at 60 fps) to drop. I think from there some experimentation may get you pretty far in terms of some of the rest. These two statements imbedded in each object will take you to the frictionless state at least in terms of projectile flight
onstart{ setLinearDamping(0.0) setAngularDamping([0.0,0.0,0.0]) }I'll look around for the proper posts but hopefully this may help some.
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Thank you for your help, I'll make some tests as you suggest. I will be very thankfull if you can find out anything else.
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You might want to take a look at this post:
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I was wondering what the unit of density in SP is?
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