If a MOSPixel has the following variables set:

Mass = 0
HitsMOs = 0
GetsHitByMOs = 0

Why is it so slow? A thousand of them drag the sim rate down.

Is there any variable or a function that will disable terrain interaction entirely, for particles that are just there for looks?

Would explicitly turning deepcheck off help any, or a specific material setting improve performance?

Not that i know of. It's just slow because... Well, 1000 particles at once. Best thing to do is to try and lower the amount of particles somehow (MOSParticles perhaps). I don't think MOPixels have deep check at all, so turning it off probably wouldn't do anything. Don't hold me up on this, but MAYBE the sim doesn't like 0 mass objects, so you could try setting it to something very close to 0 instead. No guarantees though.

Are we talking MOSParticle or MOPixel? You should test the difference in physics between the two and the possible slowdowns of each.

We're talking MOPixel.

That's not that many; a lot of FPS games are throwing around 3-4 times that many. It's just that most particles in most games aren't required to interact with things, clip through stuff, etc. I'd like that for stuff that's short-lived but I want a lot of them. Where do we make feature requests?

We don't. That's been a fact for many many years. Unless you can phrase it as a bug, no dice.

Exactly why do you need a thousand particles flying around not interacting with anything?

Well, let's see... decent-looking laser beams, because there isn't a straightforward beam code in the engine that stretches a single quad.

Flamethrowers that you can give to 20 guys and they can all be shooting them at once without dragging the sim down much.

Really nice jetpack flight effects doing some fancy things under the hood and using a lot of different particles.

Guys making dust trails behind themselves if moving rapidly over terrain (like, low-level flight).

Smoke and general FX situations where we want to throw around lots of particles but don't want to have much impact on sim rates.

Basically, a lot of stuff, and all we need is a new class that's basically just a stripped-down MOPixel with terrain detection and physics turned off.

If we want any physics on these things other than the very basics (InheritsVel, GlobalAccScalar, AirResistance) we'd have to Lua it, ideally.

A lot of that stuff can be achieved without using 100s of particles. You can get really nice smoke trails with less than 10 particles, and laserbeams can be achieved by using the same code as bullets using really long trails, really tight aim and no gravity interaction (there are also alternatives but I'm not going to go into depth here). I'm not a modder but even I know the stuff your describing can be achieved using very few particles.

Also yes 1000 particles isn't much if they've got no physics interactions, but you must also remember that pretty much everything in this game is a physics object, even the walkcycles are heavily influenced by physics, which isn't something that happens in other games, so sacrifices have to be made in the name of performance.

You will not get good-looking instant beams using ultra-long-trail bullets, in part due to speed limitations, period. Particles beyond a certain velocity start to get more and more glitchy (hit detection starts to go wonky, for instance), and a certain point simply cease to exist. Yes, if they go too fast, they just... stop existing. Completely.

There's also the matter of the beam appearance itself. You have a beam, but it's not going to be a particularly pretty beam.

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Those same FPS games are running on high-end engines that have been worked on by an entire team of professionals who do this sort of thing for an actual living, not just one man and a handful of his internet buddies. It's not really a fair comparison.

Well, it's hard to judge the problem from here, certainly, but I've done enough coding to know that usually, taking features out (i.e., skipping physics) is usually one heck of a lot easier than putting stuff in.

Particle systems are pretty simple code, imo, but I've written a couple of them, so my perspective is maybe a little different than most people's

To give some perspective I made a small engine using SDL that ran fine with 5000 small objects that had random movement (a few different variations for different types as well) and collided with (well avoided really) the map seam and terrain but had no physics or rotation. I made this in less than a day and I wasn't a very good programmer at the time (couple of years ago now). I just ran it with 8000 objects and I was getting 45fps... Granted there wasn't much else going on other than the player stuff http://i.cubeupload.com/Lv4ZRE.png (I'm not particularly proud of this so you're lucky I'm posting it to back up my claim). Even Arne can do 1000 AI without too much lag http://androidarts.com/smb/1000surprises.png.

Basically a class with only bare-bones physics that does not collide would be blazingly fast compared to even MOPixels. I think it would be worth it, it would make the game run explosions and many other visual effects faster and open up a load of Lua possibilities. Even with all the current stuff taking up a lot of fps I think this would let you could add at least 1000 of this new class without severely limiting fps, probably can't say the same for MOPixels and for MOSRotatings there's not a chance in hell. (I tested a lot of this stuff a while ago, there's also issues with settling to terrain)

Simple particles can be really cheap, yup.

Heck, once particles are built, you can just hand them over to a shader and let the GPU do all the work, so that the main costs are on creation, using vertex attributes

Collision detection is very not-cheap, comparatively. I'll be the first to say that I don't have the foggiest clue how it works on this engine, other than it must use a great deal of brute-force when it's detecting the ground, probably a search of the nearest pixels every sim frame.

Anyhow, doing a shader-based method is probably out of scope, but just having a flag that causes the particles to not display an Atom and do collision stuff would really speed things up a lot

You're forgetting that each and every one of those particles is checking against terrain every frame, too, using a per-pixel raycasting system. It's a little more complicated than a simple particle system.

That's what I'd like turned off, yes.

If it's just a visual effect, we don't need to do any raycasting and it's allowed to drift freely through terrain, which sounds bad but for the kinds of things it'd get used for (fast explosion FX with a lot of sprites, jetpack effects, flamethrower master particles spitting out a bunch of sprites every few frames, anything where sheer particle count is about the only way to get it done or add randomness) the speed tradeoff is worth it imo

Scrap the MO, just give us the Pixel!