time to code
Try interacting with the HTML5 Canvas window here. Move objects by using your mouse or finger to drag and fling them.
More on the demos...
- use multi-select to select ONE spring
- copy it (ctrl-c)
- reset the multi-select list (release the shift key then click on an empty spot in the canvas)
- use multi-select to select a new pair of pucks/pins
- paste the spring (ctrl-v)
- Dissect (or add to) the jello matrix in demos #6 and #8.
- Select a compound object (like the triangle in demo #5) and change the connecting spring lengths while it's spinning.
- Delete some of the pucks in demo #3. Select and delete without using the freeze button. Notice how the new holes in the puck grid propagate after wall collisions.
On the left side of the canvas a spring is mounted on two pins. This can be used to copy a spring (shift key, then mouse over the pins, then ctrl-c) and paste it onto a pair of pucks (release the shift key and click on an open area, then with the shift key down, mouse over two pucks, then ctrl-v).
The "Freeze" (stop translation) and "R" (stop rotation) buttons are especially useful in this demo.
This is another good place to try the editing features. Use multi-select to select the three springs on the triangle (hold shift key down then mouse over the three pucks), then adjust their length, as a group, using the "s" and the up/down arrow keys. Try copying and pasting a spring.
The editor's multi-select feature is useful for carving/slicing up the jello. Hold the shift key down, then mouse over pucks in the jello grid. A first ctrl-x will delete selected springs, a second ctrl-x will delete the selected pucks.
The controlled pucks are inelastic here to make them a bit easier to drive (bullets are elastic).
Below the "pause" control is a selection control used in establishing a fixed timestep for the physics-engine (inversely related to framerate). This should be set to a value corresponding roughly with (or be slightly less than) the refresh rate of your monitor. Generally just leave this at 60 Hertz unless you have a DVI or Display Port connection to a monitor that can render at higher rates. The longer timestep of the 30 Hertz setting will generally introduce instability in demos that incorporate springs.
If you do have high-refresh-rate gear, try setting your monitor to a refresh rate that the demos can easily match. If a demo is running slower (fps) than your monitor's refresh rate, try reducing your monitor's rate (in Windows 10, right click on the desktop, then "display setting", then "advanced display setting", then "display adapter properties", then "monitor" tab, then change the "screen refresh rate"). Then, after you have dialed back your monitor to the point that the demos can match it, set the timestep control to agree with that value.
At the beginning of the timestep select list, you'll see the option "variable". This lets the physics timestep (framerate) float along with the refresh rate of your monitor. This can be handy for observing the fps performance of your system. Generally it's best to test with this then set a similar fixed timestep value.
There's even a back-burner plan to make a new Waconia charting page based on Google Charts and Fusion Tables: all client sided to avoid hosting costs. Some folks connected to the Richland, WA airport are patiently waiting for this one.
A note on what's coming next...
Edit walls & pins