[r3333] Bouncy chargers can escape through walls!

[printz]

It seems to happen rarely, but here's the thing: if I make a Lost Soul-like monster that bounces off walls (in a classic way), sometimes it may get off the map (I saw with my very eyes how a monster phased through a wall). Here's a screenshot of it out of the map in E3M2:

And here's the wad, so you may see the DECORATE configuration. You can test the monster in any map containing lost soul mapthings. The monster is a realm667 submission, it's no secret.
http://speedy.sh/K3ru4/dlic.wad

[randi]

Can you record a demo of it happening? That would be best for reproducibility.

[printz]

Unfortunately it may take a long time until it happens again, but if I manage to, I'll send the demo to you. I'll just have to make sure to write -record first...

[Ravick]

Hum... I dont know if its related to this bug, but some actors I've made that throws many bouncy actros often throws some of them thought walls too.

[Xaser]

It's indeed bouncing objects in general that do this. The Bloodmoney drops in Psychic can occasionally phase through walls.

[FDARI]

Description reminds me of my java pong thing (when I tested my ability to make a game with java). Bouncing things would occationally round their position off so that they were at the other side of the obstacle, and because they were bouncing, crossing that boundary would not destroy them/trigger an event. Bouncing things could therefore end up detecting a bounce only to bounce on the wrong basis (actually bouncing in the same direction they were already travelling).

Lack of precision (even floating point won't be perfect) and non-destructive encounter with a boundary may cause some miscalculation. Just a guess at this point. If I find the courage, perhaps I'll look at the code. Bugfixing is a great way to discover new parts of the engine!

[printz]

It's indeed bouncing objects in general that do this.

In MBF it doesn't happen.

[Tapwave]

That looks like a job for bouncy

[randi]

File not found. It has been deleted or it never existed at all.

[printz]

OK, it seems attacheable actually.

EDIT: you might have to change the monster to replace the lost soul or anything else that's common in the game already. I think I forgot to change this uploaded's Decorate definition.

[randi]

Whelp, I tried summoning LostSouls and letting them run around but couldn't get it to happen. I'm going to need something where I can easily reproduce it, or I can't fix it.

[printz]

Yeah, unfortunately it happens quite rarely.

[siealex]

Try it on a very slow machine.

[randi]

The speed of the machine is irrelevant, since the play simulation happens at a fixed rate.

[Edward-san]

Or try to reproduce that with a lower tic rate (from 35 frames per second to 20 per second, for example), but obviously your movement will be slower as a consequence.
How? In src/doomdef.h in line 59 change the '35' value near the TICRATE macro.