Announcing Tesseract...

by eihrul on 04/18/2012 00:48, 137 messages, last message: 08/19/2013 16:01, 166139 views, last view: 04/19/2024 06:51

What is Tesseract? Tesseract is a sort of Frankenstein's monster that escaped the lab when I ripped out the static lightmapped heart of Sauerbraten, squished it under-foot with extreme prejudice, and stitched it back together with deferred shading and shadowmapping.

Run-down of the cool new features:
deferred shading
HDR rendering with tonemapping and bloom
omnidirectional point-light shadowmaps
sunlight cascaded shadowmap
screen-space ambient occlusion
screen-space water reflections (no more reflection plane limits)
refractive alpha cubes
refractive glass material

A dorky video of some of this stuff in action:
http://www.youtube.com/watch?v=ZkFT1ra2w-A

The actual code is at a github repository for the moment:
https://github.com/lsalzman/tesseract

See the README for some more details about running it.

The code is still under Zlib license.

The work on this code was done in collaboration with Benjamin Segovia over the last month or so.

The codebase is still in a state of high flux, so I would expect a lot of changes coming in the future.

The goal of all of this is not really to replace Sauerbraten and development on Sauerbraten itself will continue into the future. This is just a fork, a what-if experiment to see what it might look like if it dropped all concerns about compatibility and good performance on old hardware and just tried to modernize.

In fact, while it can load Sauerbraten maps, the lighting model of Tesseract is roughly incompatible, as not only do Sauerbraten maps use way too many lights, but Tesseract renders the lights a bit differently.

Tesseract is not at this moment endeavoring to be a stand-alone game, but just another parallel codebase people interested in the engine can choose from to work from if they want to mod it into a game of their own.

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#57: Real-time light updates

by Laraso on 06/21/2012 05:01

Is there any chance that some of these features might make their way into Sauerbraten?

I watched that YouTube video and my jaw dropped once I saw the real-time lighting updates.

It takes forever to place and edit lights on a map in Sauerbraten, and that feature would make it incomparably easier.

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#58: Re: Real-time light updates

by suicizer01 on 06/21/2012 21:44, refers to #57

placing lights isn't the actual problem. You'll learn that if you done it some more times.

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#59: ..

by spiney_. on 06/24/2012 22:35

Improved tonemapping, yay!

Here's some screenshots of the bounced sunlight in action.


http://img201.imageshack.us/img201/8481/tess01.jpg
http://img804.imageshack.us/img804/2752/tess02.jpg
http://img571.imageshack.us/img571/3826/tess03.jpg

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#60: Re: ..

by geartrooper2 on 06/25/2012 00:31, refers to #59

very nice. gj lee.

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#61: State of the Tesseract...

by eihrul on 06/29/2012 13:03

Just a quick development summary for those who have not been following Tesseract much, but might still be interested in what has gone on with it since the initial code release... In no particular order of importance:

* Shadowmap caching feature that eliminates almost all shadowmap drawing costs in each frame, and some new light entity modifiers that mappers can use to take better advantage of this.

* Morphological anti-aliasing using the SMAA algorithm (also known in the past as Jiminez' MLAA in earlier versions). It's not as nice as MSAA, but it's cheap and works well with deferred rendering.

* Water caustics were added back in.

* Fullbrightmodels was added back in.

* Made spotlight ents work again. The resolution with them may be a bit wonky at the moment depending on the radius you set them at, but otherwise they work. Flashlight lovers rejoice.

* Did some library plumbing to make it so you can cross-compile Mingw64 builds to get 64 bit Windows binaries if you are brave.

* Sunlight now does real-time global illumination. It isn't exactly skylight, but it is nice in a similar but different way for brightening up dark spots in your map and adds a subtle color bleeding effect. And, it's dynamic/real-time still!

* I recently got my hands on an Ivy Bridge CPU, and I got things running pretty well on the HD 4000 IGP. Some things like SMAA still seem to not entirely work, but other stuff like the sunlight GI and SSAO and everything else is running pretty well.

* The HDR system has been rethought to give much saner results. After a few failed and frustrating week-long experiments that died on my hard drive without ever touching the repository, I struck upon a stupid simple idea that I should have thought of before...

The goal of HDR is not to brighten the crap out of dark things, or darken the crap out of bright things. It is simply to preserve feel of the lighting the mapper made as accurately as possible, no "if"s, "and"s, or "but"s. In hindsight, this is stupidly obvious, but almost nowhere is something like this written about or tried, since it involves reversing the tonemapping: match the output luminance on the monitor of some scene average to the average input luminance, within a given allowable range. Obvious, but strangely overlooked.

So the HDR system now does exactly that. It does not fight the mapper's lighting in any way. It just allows you to have more controlled saturation of colors and allow some viewing of things in the nigh-invisible black range, along with the tried and true "Oh, god, my eyes!" bloom effect. So if you turn HDR off, the maps still look pretty good, just now they look subtly better with HDR, a slight boost in contrast and bloomy stuff.

So, really, I can't think of terribly much more that could be added in terms of neato rendering features to the engine within what I envisioned for it, they're all pretty much covered now. I think the engine is getting pretty stable now despite all the new stuff added to it, so in a roundabout way, it is actually not much more less safe than the default codebase to base new projects off of, for sufficiently limited interpretations of "not much more less safe". I hope someone, at least, is having fun with it.

Over and out...

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#62: Re: State of the Tesseract...

by geartrooper2 on 06/29/2012 16:34, refers to #61

congrats on the revelation.

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#63: ..

by Razgriz on 06/30/2012 06:59

"I hope someone, at least, is having fun with it."

You bet your ass we are :P

And i don't know if it counts as a rendering feature, but there's quite a bit of unhappiness surrounding the fog rendering.

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#64: Re: ..

by eihrul on 06/30/2012 07:22, refers to #63

In what way?

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#65: ..

by kripkenstein on 06/30/2012 07:41

I don't seem to get any water rendered, is that expected?

Otherwise OMG this is so amazing, I love just moving lights around and seeing how things look. It's awesome.

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#66: Re: ..

by eihrul on 06/30/2012 08:04, refers to #65

It's safe to say broken things are never expected. I don't even think it's appropriate to ask that. :)

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#67: Re: ..

by Zamwa on 06/30/2012 08:34, refers to #63

I'm happy with it lol!?

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#68: Re: ..

by xoltan on 06/30/2012 08:50, refers to #63

As far as fog goes, I'm not sure if Razgriz's problem is the same as mine. With wider aspect ratios and fields of view, the left and right edges of the screen aren't clearly less foggy than the center of the screen. I'd guess that it has to do with something being planar instead of cylindrical.

Not the best examples, but ones I have handy:

http://www.xoltan.org/files/terrain01.jpg

http://www.xoltan.org/files/terrain2.jpg

Not Tesseract, but it behaves the same.

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#69: Re: ..

by Q009 on 06/30/2012 11:45, refers to #68

Holy shit, nice terrain work

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#70: Re: ..

by Razgriz on 06/30/2012 14:24, refers to #68

Yes, that's the part i don't like about the fog really, it's planar and not spherical, which seems weird in a variety of cases.

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#71: Re: ..

by Razgriz on 06/30/2012 14:42, refers to #70

well, my point is, with all the fancy things tesseract offers, it feels wrong not to work on the fog too :P

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#72: Re: ..

by Zamwa on 06/30/2012 16:35, refers to #68

I really don't notice it to be a problem unless I set /fog under 300! What I'd like to control is the transition thickness of fading! Like a command /fogfade would be sweet!

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#73: Re: ..

by Q009 on 06/30/2012 16:49, refers to #72

Here, have this potato, sir.

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#74: Re: ..

by eihrul on 06/30/2012 19:25, refers to #70

Spherical fog, maybe. Exponential fog, maybe. I played with them, but they were problematic in their own ways. One day, fog may improve, one day.

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#75: motion blur

by spiney_. on 06/30/2012 19:56

I really like the way it is now :)

The one thing I would like to see improved at some point though is the camera motion blur. At the moment the motion blur is really more of a ghosting effect. Something like Valve added in the Orange Box would be nice, HDR or not...

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#76: Re: ..

by Razgriz on 06/30/2012 23:38, refers to #74

now i'm curious to know what those problems were about :D

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