Shading and Lighting in Shadowgun

Hi guys,

I hope you like what you see on all the screenshots and videos of Shadowgun - the new game by MADFINGER games.

We try to shed some light on the tech behind the pretty pixels in this blog post. Enjoy

 

Excellent post and great looking visuals Robert. Those guys deserve the spot on the front page

 

Ooh advanced, me like

 

looks nice.. I suppose this will be new feature in unity.. are probes baked with beast?

 

Screens are nice! Unity really laid on these fps demos!
Maybe the next "COD" will be a Unity game!

 

Ahaha good one

 

@cupsster: Yeap So they get the awesome Beast's GI, can be baked together with lightmaps or separately. After the main GI calculations are done, baking the probes is pretty fast, so you can iterate on re-baking the probes quickly. And when baking lightmaps at the same time you won't notice the added time much.

 

Awesome work guys. I'd very much love to see this feature integrated in Unity, along with directional/RNM lightmaps.

My question would be why split into tetrahedra instead of using a simple octree?

 

That's a good question. And there's a couple of reasons, actually.

If you're thinking about a solution where probes would be nodes of the octree, then it's actually not much better solution than a regular grid. It still needs to store visibility in every probe to avoid probes within or past walls to leak through those walls. There's not much artist control on where to place the probes (which is a problem in itself), so the local resolution will usually be many times higher than actually needed, which will make an expensive technique (bigger memory footprint due to the need of storing visibility and more complex interpolation) even more expensive. The interpolation is also more expensive and complex, as not only the 8 probes forming the current cell need to be taken into account, but also potentially some extra probes from the adjacent cells if the adjacent cells have different size than the current one.

I discussed a bunch of related techniques in this blog post, but that was a while ago and my concept changed a bit. Still any suggestions are very welcome

 

really nice render , fantastic

 

Sounds like a robust lightweight alternative. Thanks for clearing that up.

 

Like it

 

I thought the screenshots of this looked great when they where posted a few weeks back, but compared to the video they didn't do it justice! It's amazing how much of a difference the light probes make to the charcater lighting. Looking forward to having a play with those

 

will this stuff in some way do RNMs? or somehow make the baked lightmap effect the normal maps?

 

It's mostly for dynamic object to get some GI like lighting. It's not really for added speculars etc to things that have proper lightmaps. At least from what they've shown so far, it doesn't look like the implementation will have anything to do with RNM.

 

Damn... thats the one thing that really bugs me about unity.. this whole dual lightmap system is just lame. Kinda wish we had a choice to use rnms in beast or something.

 

Very impressive, yet inspiring, not intimidating. Encourages me to raise my game.

 

I'm using the Unity 3.5 beta. I love the beast lightmapping system and light probes! I was wondering how ShadowGun was able to accomplish muzzle flashes lighting up their characters.

Since the characters are constantly moving around throughout the scene how does that work?

Thanks!

 

I'm hoping that this shader will be made available to us from unity, and optimised for mobile, where it matters the most of all

 

That was actually a very simple thing to do. Shadowgun sets the max number of pixel lights to 0 and the max number of vertex lights to 0. That causes the normal fallback mechanism in forward rendering to force ANY realtime lights directly to SH.

So the way lighting is calculated for the character, is that Unity first gets the interpolated SH probe calculated based on the baked probes. Then Unity searches for any realtime lights that might affect the character, casts them to SH at the character's position and adds the resulting SH probe to the interpolated probe. That gets set as the shader uniforms.

The shader samples SH per vertex as usual (and then calculates the directional light per pixel).

You can set the max number of pixel lights to 0, but setting the max vertex lights to 0 isn't possible yet - we want to solve it nicer for the next version, so that you can have more control over which lights exactly will get casted to SH.

In the meantime you can still achieve the exact same effect, but requires some effort. You will need to call GetInterpolatedLightProbe() yourself first. Then find the lights you want to affect the object and cast them to SH same way as the code examples in LightProbes.coefficients do. Finally pack the coefficients into shader uniforms as described here in A10 and sample them in the shader (as described there, which is what Unity's ShadeSH9() does).

It's very simple, but may sound intimidating, so we'll figure out a nice way to configure lights that way for the next release.

 

Is there any chance now that 3.5 RC1 is available that there will be a tutorial on how you were able to achieve such amazing lighting and shading in shadowgun?

It would greatly appreciated!

 

I think REJ might have a shader that we can apply that just works. But you will have to sacrifice your 7th child for it and run backwards naked around unity hq 3 times.

I really like the information about lighting up (muzzle flashes/explosions) for free, Robert. Thanks!

 

7th child sacrificed, the headquarters is a bit far from LA but I'll start running backwards now.

 

No sign of said shader yet

 

Ancient thread being ressurrected - but did this ever become possible to do? - in 4.5 there's still no obvious way to limit the number of vertex lights.

I'm currently implementing my own vertex lighting solution, as Unity's vertex lights still don't work with lightmapped objects - and wondering how to also apply these lights to lightprobe-lit objects.

 

I thought about an option on a light to force it to SH, but never did it. I might revisit it post-5.0.

In the meantime you can use these examples I wrote to add contribution from your lights to the baked light probes.

In 5.0 the functions from the above examples are built-in.