How do you make a mist/smog effect with particles?

Niborius on 21/3/2022 at 14:03

For my upcoming Thief 2 mission I'm trying to add a mist effect here and there to give the city some atmosphere. Like hovering about the ground or near distant towers.
To show you what I mean, here are some examples:

(https://miro.medium.com/max/1400/1*t6-cNvNivbCuQ72I0tNO2w.jpeg) Example 1

(https://images.gnwcdn.com/2013/articles/1/7/0/1/9/8/0/bloodborne-is-a-souls-successor-with-serious-bite-140854790297.jpg) Example 2

I've been fiddling around with particle effects but it just looks off everytime. Any tips?

ZylonBane on 21/3/2022 at 17:24

Use large bitmap particles with a slow random spin, long lifespan, slow fade-in and fade-out, and low alpha. Experiment with them being lit vs unlit.

trefoilknot on 21/3/2022 at 17:35

I think Nameless Voice made a pretty cool mist effect. (Hazelshade Cemetery, IIRC?) Not sure how he did it, but maybe you can crack it open and see if it'll work for you.

Niborius on 21/3/2022 at 18:43

Thanks both, I'll experiment with those settings and will definitely check out NV's version to get inspiration how he did it!

ZylonBane on 21/3/2022 at 19:49

(https://www.youtube.com/watch?v=gHp-midNmxQ) HazeCem doesn't use particles. It uses multiple scrolling worldspace bitmaps with transparent fog textures.

nicked on 22/3/2022 at 13:36

Just be very careful to keep an eye on your framerate. Nothing eats performance quite as fast as large amounts of particles onscreen at once.

ZylonBane on 22/3/2022 at 21:48

Quote Posted by nicked

Nothing eats performance quite as fast as large amounts of particles onscreen at once.

Completely wrong. Nothing eats performance quite as fast as large amounts of AIs onscreen at once.

Particles, on the other hand, can easily number into the thousands before your frame rate takes a noticeable hit.

Niborius on 23/3/2022 at 12:26

Just a quick update that this:

Quote Posted by ZylonBane

Use large bitmap particles with a slow random spin, long lifespan, slow fade-in and fade-out, and low alpha. Experiment with them being lit vs unlit.

worked perfectly for me. On some occasions I use lit and other times unlit.

So far no drop in performance.

john9818a on 26/3/2022 at 12:57

I remember Masque of Red Death had a low fog effect which IIRC used the conveyor belt with a fog texture.