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[Blink]

First off: I am really bothered by the new Tomb Raider's fire effect. It's flat and wiggly and it doesn't look much like fire - it's basically a video on an animated polygon that's probably a couple planes stuck together with a billboard effect.

Then, however, I came across this:





The more I share it, the more I think of it, so now I'm posting it here. I really hope this approach takes off, because imo it looks fantastic compared to the stuff we see right now (which looks like his nebula with the opacity effect disabled).

That's all!

[Christian Knudsen]

That works great for a gaseous and shapeless nebula like in the video, and it might work okay for fire effects, but it'll be terrible for trees and other more tangible objects. Imagine looking at a tree in a game, but as you circle around it, you'll see the various branches fading in and out of existence.

[JamesK]

Nice!
It certainly produces good results and isn't at all complex.

[UltimateWalrus]

Awesome technique, thanks for posting.  I wonder if you could make vegetation look good if you used a shader to make the leaves sort of bleed out instead of fade out.

[Shadowspaz]

I'm really loving the simplicity behind this. I am curious how this would look applied to fire, though. A nebula really has no shape, but a fire (Think of a campfire, for example) will tend towards a triangular shape. I'm thinking you could use triangle planes, at randomized angles (Maybe meeting at a point at the top, maybe not) to get the proper three-dimensional shape for the flame. Also, while the nebula in the example fades out to nothing, flames are pretty rigidly-defined, so I'm not sure what that would do to the effect. But this is all speculation, and I'd love to see what develops from this.

It would definitely be a fantastically fun thing to play around and experiment with.

[RandyGaul]

That works great for a gaseous and shapeless nebula like in the video, and it might work okay for fire effects, but it'll be terrible for trees and other more tangible objects. Imagine looking at a tree in a game, but as you circle around it, you'll see the various branches fading in and out of existence.

Actually it looks great on trees: http://the-witness.net/news/2011/06/witness-trees/

[Christian Knudsen]

I'd like to see a video of a player circling one of those trees at close range. It's not really something you can judge from stills. But I guess I stand slightly corrected for the time being.

EDIT: I'm also not a fan of the dithered effect used to fade out the branches. I guess it's cheaper than proper alpha transparency?

[Blink]

The dithered effect is definitely strange, but the trees look way better than I expected they would. And yes, that depends on the rotation too (maybe that's why they chose dithering?) but even so, these are great results. Thanks for the link RandyGaul!

[BorisTheBrave]

Here's a variation of the technique for fire:

http://simonschreibt.de/gat/tomb-raider-laras-hot-secrets/

[Polly]

I'm also not a fan of the dithered effect used to fade out the branches. I guess it's cheaper than proper alpha transparency?

It's to prevent the need for sorting the polygons back-to-front in real-time ( and splitting intersecting polygons somewhere in the pipeline ), apart from the additional performance hit you get from blending. Using dithering a simple alpha test will suffice, and when desired you can smooth out much of the "crude" dithering look using anti-aliasing / post-processing.

[powly]

This is cool indeed - what I didn't know was that it was new, since a lot of games have already done this. Could someone care to elaborate about this fuss?

[Christian Knudsen]

It's to prevent the need for sorting the polygons back-to-front in real-time ( and splitting intersecting polygons somewhere in the pipeline ), apart from the additional performance hit you get from blending. Using dithering a simple alpha test will suffice, and when desired you can smooth out much of the "crude" dithering look using anti-aliasing / post-processing.

Thanks for the explanation.

This is cool indeed - what I didn't know was that it was new, since a lot of games have already done this. Could someone care to elaborate about this fuss?

Well, the video in the OP is three years old, so I suspect this is just the first time the OP has come across this technique?

[Blink]

Actually, I came across it almost a year ago. But I still don't see it used in most games! And that's a real shame, so I'm just trying to bring awareness to it - and remember to do it myself.

EDIT: Also, thanks for the link Boris. Definitely learned a lot, but I still can't stand this effect:



There's got to be a better way. I'd prefer the separation of particles at this point even.

[Christian Knudsen]

Yeah, that stretched out flame looks terrible. Maybe they could have a secondary loop of frames where the flame was "torn" apart, and when the plane is stretched beyond a certain threshold, it would switch to those frames temporarily?

[Trent]

Ha, the gif loaded slowly for me, and the first few frames got me thinking... "Hey that fire looks pretty good!"

Then dat stretch.