Algodoo

This is an interesting and fun scene. Nice job!

Here are a few comments, suggestions, and questions.....

1. Step #1 in the widget states: Right-Click yellow circle
and "Use as Chain". Logically that command tells me to right-click the yellow circle, and right-click "Use as Chain" which won't work as expected. So I think it would be less ambiguous if you changed that to: Right-Click yellow circle, then Left-Click "Use as Chain".

2. What does "Reset Array" do, and how should it be used?

3. You explain how to use the yellow circle in the widget but not the blue circle. What is the blue circle's purpose in the widget?

4. As is the case in other similar scenes you've done with tracers, it would be a nice feature to be able to adjust the size of the tracer, the color, and the fade time. Maybe do those things with a convenient widget with sliders.

Oh, one more thing.... You might want to mention something about adjusting the "link distance" of the chain in order to make the animation more or less smooth. When I first started this scene, my link distance just happened to be set to some large number which made the animation look horrible.

Regarding #1, I agree. Thanks. I will fix that.

Q: What does "Reset Array" do, and how should it be used?
A: "Reset Array" clears the path array. The array should be empty before drawing with the chain. The problem is that the array automatically gets filled with the sample link entityIDs when the widget is spawned.

Q: You explain how to use the yellow circle in the widget but not the blue circle. What is the blue circle's purpose in the widget?
A: The blue circle is required to complete the chain link. The yellow circle adds its entityID to the array upon spawning. Once the yellow circles are created, the blue circles and hinges are no longer needed. The yellow circles are left so that you can change their position if desired. If you don't need to adjust the yellow circles, then you can skip steps #4 and #5. A drawing can be made up of several chains. The reason for two circles instead of one box is that I wanted to record the position of the hinges, not the center of the link.

Q: It would be a nice feature to be able to adjust the size of the tracer, the color, and the fade time.
A: I did not include that since that widget is already available in Algodoo. The tracer base circle has a _blank property that is true for retrace blanking and false for continuous loop. The base circle also has a _cycleTime property that automatically gets set in the onSpawn event.

Q: You might want to mention something about adjusting the "link distance" of the chain in order to make the animation more or less smooth.
A: I agree. I thought the link distance got saved with the scene, but apparently not.

In case you did not know this, you can force selection of the chain tool and its link distance as shown in the following script:

Tools.ChainTool.SelectTool;
Tools.ChainTool.LinkDistance = 0.05

You can put that in "onSpawn" if appropriate.

I knew about the first line of code but not the second. I updated the widget to set link distance to 0.05 on startup.

Wow!

Thanks.