Create kinematics free fall world

[MarkMcGregor-dev]

This completes the prototype of the Kinematics Free Fall experiment (experiment 1/3).

TO TEST:

Accessing the experiment world:

• Launch Circles and login
• On the explore section, visit the Kinematics Lab - FreeFall

Starting the experiment The experiment is controlled by the control station directly across from the starting position. Simply walk over to the control station and use the buttons to control the experiment.

• The 'Start' and 'Reset' buttons should engage and reset the experiment respectively
• Pressing the start button should trigger both timers to start counting, and both objects should hit the ground around the same time (timers should be exact or off by 1 digit).

Changing objects Both objects can be changed by pressing one of the three object buttons on either side of the control station.

• Pressing a different object button should change the corresponding object mesh (visible in the hand)
• Pressing a different object button should change the floor text indicating the mass of the object - this should be the same as the label on the control station.

Changing gravity The experiment's gravity level can be changed at any time (including during the experiment) by pressing the increase or decrease buttons on the control station.

• Pressing the increase button should increase the gravity (objects should fall quicker)
• Pressing the decrease button should decrease the gravity (objects should fall slower)
• When gravity is set to zero, the objects should not change momentum (unless colliding)
• Changing the gravity should be indicated by the control station's label and the floor text
• The gravity control should be restricted to 0-3g at 0.5g increments

[PlumCantaloupe]

Great PR @MarkMcGregor-dev!

This all looks to work well. I tested on Desktop, Oculus Quest, and a Samsung S6 lite Tablet and they all seem to work. Also, the style is great - very "portal-esque" :)

Just a few comments:

1. There is a bug when selecting different models using the buttons on the left and right. It just seems that the model path has changed as you now have them in the "experimentObjects" folders under assets.
2. We should have some circles-checkpoint's around so people can navigate without having to use WASD keys. This also means that users on a mobile device or Quest can move around, as they are stranded otherwise 😬
3. The weights seem off for the soccer and tennis balls i.e., they don't bounce enough it seems at 1g and below ...
4. There was a small bug where the objects fell through the floor on the Quest. I couldn't recreate and refreshing fixed it; but just an FYI.
5. I wonder if we should just have a placard with the equations the requirements asked that we use somewhere?
6. Why is the spawn point away from the controls? Was this a design decision so that users have to move around to find them?
7. In the future, for further polish, consider adding sounds and a nav-mesh. Also, many of these GLB assets seems larger than necessary. If we export from Blender we can export with images where we can then re-size them manually to reduce image sizes. If the issue isn't image sizes perhaps they have too many polygons ... around 20mb is where we hope to average out in general; but for this fidelity, we should probably be able to get closer to 10mb.

P.S. I made a small commit to re-organize the placement of this world on the "explore" page.

[PlumCantaloupe]

Going to merge this; but one note that the bear's "hand height" isn't set the same as the other objects so it hits the ground before the other objects.

[PlumCantaloupe]

The bug fixes and checkpoints are good.