On: Show HN: Lunar lander-type game with computational fluid dynamics

[artursapek]

Very cool and great use of webassembly. Bug report: if you get low enough in the last level and thrust upwards, the black smoke somehow mixes with the purple smoke outputs and they start instead covering the screen in black smoke.

https://i.imgur.com/vHOrBWm.png

[s-macke → artursapek]

I guess this is the problem I mention in my code here: https://github.com/s-macke/Interplanetary-Postal-Service/blo...

For the sake of optics I use wrong boundary conditions for the colored part of the fluid (transport equation).

The right solution would be to copy the density[]-grids and apply the wrong boundary conditions on them and then draw the image with it.

[misnome → artursapek]

I also had problem with the last level - on the several attempts I had left, after about 10 seconds the sim would seem to bug out and it looked like there was a very, very strong wind along the bottom, which looked like it was friction-pulling the rest of the play area so that everything was blowing fast to the left, leaving it (apparently) unplayable.

Good fun, otherwise.

[s-macke → misnome]

Damn. I thought I have solved this issue. But why does it work for most other players?

[cellularmitosis → s-macke]

I ran into this as well. Here's a video: https://youtu.be/SomX22VGHHc

It doesn't always happen for me. Here, I had to play through the game several times before I could get the bug to trigger.