Energy chunks returning to beaker can disappear

[chrisklus]

Because of the clipping region in place on the beakers (see #114), energy chunks that are owned by the beakers can only be seen within the red column shown below. When a beaker is receiving an energy chunk from the air, it owns that chunk as it's on its way down, so if the beaker is moved away from the traveling chunk, then the chunk disappears until it reaches the beaker and magically appears in the fluid. This bug is present on master and 1.0.

The reason this is not an issue for energy chunks that the beaker releases is because the air owns those chunks as they ascend, so they do not need to remain within the beaker's clipping region in order to be seen.

Assigning to @jbphet and me to fix, and @ariel-phet for prioritization.

[ariel-phet]

I am going to put this one as high priority since the fundamental goal of the sim is energy conservation, so it seems a problematic bug from that standpoint.

[jbphet]

I've added code that causes the energy chunks to move with the destination object in the horizontal direction in this situation. @chrisklus and I both thought it looked pretty good. Marking as fixed, but will leave open and have QA verify in the next release.

[KatieWoe]

This seems to be ok in 1.1.0-rc.2. I did notice that the last bit of the the energy chunk falling is much faster if moving the block/beaker at the time. I believe I also saw the energy chunk show this behavior by chance since it spawned near the clip area and zigzagged in and out. However, I haven't been able to replicate this behavior since it seems to happen by chance.

[KatieWoe]

Update. Please disregard the second part of the above comment. I think I am misremembering and this actually happened on the the old version while I was testing to see what the bug looked like. I'll keep trying for a bit, but unless I can reproduce only speeding up chunks from the comment above should be considered. Sorry for the confusion @chrisklus

[KatieWoe]

Haven't been able to reproduce on this rc

[chrisklus]

Thanks @KatieWoe! The returning energy chunks speeding up when moving the beaker is intentional. That's great that you haven't seen them zigzag in and out of the clipping area.

I think we're ready to close here.