Kristine Tseng 4/8/2020

Sketch

I wanted to make a Rube Goldberg machine that inflates a tube man. My original sketch for a Rube Goldberg machine had more components than I actually used. The resulting animation omits the lever and ball bounce because I didn't have time. I also replaced the wheel with a Pringles can.

The most difficult part of the animation was surprisingly the dominoes and not the tube man. I had a lot of trouble figuring out how to make the dominoes fall off the table and not slide around on empty air after passing the edge of the table. Eventually I realized I could add the table as a collider and move the ground plane to the actual ground. Adding the table as a collider should have worked, but the dominoes kept falling over before the previous dominoes hit them as if the table was too slippery for them to stay upright long enough for the domino chain to fall down in order. Increasing the friction, mass, and whatever other attributes of the table did not seem to stop this from happening at all. Eventually I fixed it by just making the dominoes fatter and increasing the friction on the table by a lot.

I tried to use an nCloth for the rope on the pulley to make a more realistic rope, but couldn't figure out how to get it to sling over the pulley. I might have figured it out if I did some more investigating but what I ended up doing was putting two long skinny cylinders on either side of the pulley and keying the lengths of the cylinders to make it look like the rope was moving.

The tube man took some working with to figure out but I am mostly satisfied with the result. I modeled it with three cylinders and the union operation, made it into an nCloth, and used nConstrain to attach the bottom of the man to the base. Then I played the animation, watched the tube man fall, and picked a frame that looked good and set that as the initial state. For inflating it I keyed the wind speed and pressure attributes.