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Submitted by Bruno, posted on February 22, 2002

Image Description, by Bruno

These are work-in-progress shots from our new tech demo, showing off realtime dynamic shadows. Our engine, ASKYN, is able to push quite a hefty quantity of polygons at the graphics card and is heavily optimized for the GeForce family. We will include support for ATI hardware although not right away, as we are waiting until the actual game programming step is over. All elements of the scene are lighted equally, both moving and static ones, although special optimizations are done to each one. Our site is We would like to thank in advance to any one who cares to comment this post.

Image of the Day Gallery


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Archive Notice: This thread is old and no longer active. It is here for reference purposes. This thread was created on an older version of the flipcode forums, before the site closed in 2005. Please keep that in mind as you view this thread, as many of the topics and opinions may be outdated.

February 22, 2002, 05:09 PM

pfft... Im just not impressed if it isnt real time

anyone can create a very impressive scene in 3DSMAX with a million polys, export it, and render it on GeForce card in 5 minutes, and claim it is the worlds greatest engine.

if it is not real time who cares



February 22, 2002, 05:15 PM

Yes, you're right at that. I was just amazed by the current state of realtime rendering. Unless you mention more engine features, I must say that this can be created really quickly. Just take some 3d demo with source and set a different mesh. You've got a great 3d artist though.

Ben Hanson

February 22, 2002, 05:16 PM

Did you even read the IOTD post?

"Real-time dynamic shadows"


February 22, 2002, 05:30 PM


The sun icon in the top picture does indeed lack a shadow. Does that perhaps convey some deeper meaning - that as the sun does not occlude light, but rather produces it, neither should it cast a shadow? But then shouldn't the shadows fall away from the sun as if it were the source of the light, not through it as if it simply didn't exist?

Enough philosophical rambling...

Question 1:
Are the shadows cast in real time, or are they precompiled shadow maps applied to the textures?

Comments 1:
A quite interesting scene could be done with multiple lights using precalgulated shadow maps, one per light, and blending them onto the texture, that way, the intensity of the individual lights could change dynamically, enven though their location could not. Maybe one of you other readers will do a demo to show that optimization? I simply don't have time to write it myself.

Question 2:
Why are there no glasses on the table?

Comments 2:
Glasses sitting on the table would be a nice demo of refractive shadows. You would get an almost-shadow through the glass, with a focused highlight in the center caused by the refractive glass. (Confusing concept, I know, but please try to picture it in your head, or better yet, get a wine glass, a dark room and a single light source, and see for yourself.)
Those shadows/highlights could be optimized with precalculated shadowmaps (with augmentative values as well as attenuative) also whose individual intensity is tied to the light source intensity.

So, what do the rest of you think?


(btw, GeForce3 should be low end in about 2 years.)


February 22, 2002, 05:50 PM

It's amazing what nice textures will do.

Martijn Stoffels

February 22, 2002, 06:18 PM

The refractive shadow through the glass with the "hotspot" you mentioned is known as caustics, and is really a feature in advanced raytracers, not something one would implement in real time any time soon.


February 22, 2002, 06:27 PM

Really impresive guys. Hope to see somthing real soon like that on my computer:)


February 22, 2002, 06:54 PM

Am I the only one missing soft shadows, or are my glasses sharper than they've ever been?


February 22, 2002, 07:43 PM

I'm not talking about doing the causics calculations (thank you for the proper word; I've seen it used before, but I couldn't remeber it just now.) in real time, I'm talking about doing the calculations once for each stationary light source, creating separate lightmaps for each lightsource, then just doing the lightmap mixing in realtime. That way, you could turn a light on/off in real time, you could have a flickering firelight effect in realtime, you could have several flickering candles as light sources in real time, etc. You just couldn't have moving lights. Well, you sort-of could, but you would have to have a separate frame in the lightmap for each light position along the movement path. That would get really messy and the whole point of optimizing it would begin to be lost.



February 22, 2002, 07:47 PM

I suppose the signature should have been "-CyberVenom" on that last post... Oh well. "Aaron" is my real name, so I guess that's ok too.


February 22, 2002, 11:10 PM

damn, i was just about to say the same exact phrase, the shadows themselves appear nothing more than volumetric stencil, and not too impresive as they appear to project absolute darkness. which is not that realistic if you ask me.


February 23, 2002, 12:51 AM

Yes it's surprising no one except yourself has mentioned it yet. Thats the first thing I thought about when I saw the image (the sharp shadows).


February 23, 2002, 02:41 AM

Uh, isn't that two words? And I wholeheartedly agree with them both!


February 23, 2002, 03:16 AM

Now THAT is what I call impressive!! Excellent work!!!


February 23, 2002, 03:58 AM

The words of a person who never made an (game) engine and doesn't know what it takes to write it..


February 23, 2002, 05:01 AM

If it's any consolation, _I_ can tell what the thing in the middle is :p

Its a little demon, with wings, looking up into the air and spraying a fountain of water out of its mouth.

Probably be more obvious when animated though :o)


February 23, 2002, 06:08 AM

texture plays a very important thing in "impresiveness" quality.
with no texture, all the object will look the same.
the shadow is damn good.


February 23, 2002, 09:54 AM

As i first saw da shots i thought:
wow, whadda nice raytracer, time to do _this_ in realtime, haaahaha.



February 23, 2002, 10:21 AM


When someone sends in an image with a landscape that looks pretty, but not with a high polycount, nice textures and use of new features, in other words: far from reality.. nobody complains, and they all say that it's sooo nice, and looks sooo real..

When someone sends in an image with a huge polycount, nice textures, using the newest (hardware) features and realtime shadows + lights, all those people start yelling that things are missing, that it could've been done way better, etc, etc, etc.

Funny.. really funny..

Anyway, I have only one thing to say about this piece of art: Holy cow! *drewl*


February 23, 2002, 01:20 PM

Nice work. :P


February 23, 2002, 02:18 PM

Nice work!

When you mean "optimized for the GeForce family"...does it means the "GeForce 3 and 4 family" ? :) My GeForce 256 kinda feel left out in those shots :

anyway, how are you generating your shadows? Are you using vertex and/or pixel shaders?

I like the way you projected the shadow of those alpha blended polygons though, very nice (i.e the fireplace grid , and the thing on the table)


February 23, 2002, 02:22 PM

Hello to all, my name is Victor Martins ( ) and i make part of the team Gamelords, the team that produced the demo of those images. We haven't answer earlier the question of you guys because the create account option isn't working, luckily Mr Mav is a friend of ours and we are going to use his account.
Im the 3D modeler of the team, so im going to answer questions about my work, and give a general idea of the rest, my other team mates will answer the rest.
Here it goes :

What sort of framerate does this push?
This is a tech demo made to push our engine to the top, we are using dynamic lightening and so, the frame rate is about 15 fps on a regular ge force with 3 lights, with a ge force 3 that we don't have so we didn't tested it yet, it should be a lot faster.
We only use about 20% of the CPU so, the CPU don't really mater, it works on a celeron 400mhz with a ge force 2 MX

How long does it take, to load such a scene?
Very quick about 30 seconds, the models are extracted from the 3D editing software using one in house plugging and then some precalculation is made using one in house tool, so in the end they are very optimized. Our programmer can say more about this, i don't really know the details on this steps.

The thing on the 2nd. picture in the middle is...
A Dragon :) The fountain is called the Dragon Birth, and we have 3 dragons shearing for a new born that comes from the center. A little idea of mine, the light must be moved a few meters to illuminate his chest. That will be fixed on the demo.

But are you sure you can move around in the environments real time?
Very sure hehe, but the fountain is a scenery that can be seen from inside that room, trough the window, and we can't go to the fountain, but we can move around the room.

No one gets off without explaining their algorithms, how is your lighting done, and how is it unique?
Well ok ok :) but that will have to be our programmer to answer :)

Looks nice. But why doesn't the sun symbol cast a shadow?
Well this image's still have some bugs, there are a lot of shaders to work with and they are all scriptable and it takes a while to make it all pretty and clean. But the problem with the sun is because that little "medallion" is a moveable part, and we forgot to make the shadow in place, so the shadow is first made in the origin, and then we move the "medallion" . Well it's fixed already :) Good eyes dough hehe

You sure its realtime?
Very sure :) You can check that your self in the demo, it will come out pretty soon.

Pagman Questions 16th post.
The programmer will answer that on is post ok?
But very good questions :)

Looks good, but I can't see anymore than one light source in any image?
In that scene we have 3 lights one in the middle of the room, one in the fire place and one in the fountain, the demo will have more, we forgot to put the candles, it will have a light for each candle, and maybe some more. You can turn on and off the lights on the demo so don't be afraid :)

Well, there is at least no more than one shadowcasting light source in the pics...
Wrong, all the lights produce shadows, you can check that on the other screenshots on our web site front page , check the shadow of the grid on the fireplace in the floor :)

I presume with scenes that complex you use some kind of occlusion alogrithm?
Another question for the programmer...

How many polygons are these scenes?
The mesh has about 60 000 polys but each light makes 2 steps with alpha blending so in the render we have about 360 000 polys , but these don't make a difference cause we had 100 000 on the mesh and the frame rate was just 3 to 4 fps above the actual one. We reduced just to see if we had a better frame rate, and it looks has nice has before so we kept it that way.

pfft... Im just not impressed if it isnt real time ...
It is real time, don't worry about that, worry about getting a ge force at hand :)

Unless you mention more engine features, I must say that this can be created really quickly ...
Well the programmer will clear this up, we are making a page for the engine at the moment, it will online soon with all the features and stuff.

CyberVenon Question
They are dynamic we didn't use any e shadow map.
There are no glasses because the shader of them was buggy :P It's fixed already.

Well i guess it's all , for now, sorry i can't answer all of the question but the programmer and the texture artist will post here too, so please come back to check it out.
Thanks for all the comments the team was drilled by them and it made the effort worthy.
By the way our emails are :

3D Modeler
Texture designer

Feal Free to make more questions .


February 23, 2002, 03:40 PM

amazing work!


February 23, 2002, 04:37 PM

Sounds really solid. Congrats.

Matt Newport

February 24, 2002, 05:02 PM

I reckon roughly the same number of years as it takes id to finish Doom III ;-)


João Baptista

March 08, 2002, 05:57 PM

Ta boa GameLords parabéns!!
(parabéns a todos menos ao reAper| lol :p)


March 16, 2002, 12:17 PM


Finally got some time to answer this properly.

I am the texture artist responsible for the textures seen in the demo.
The only really big textures (up to 1024*1204) are the table, carpets, books and paintings on the wall. The rest are small tiles with grayscale detail files on them to create variety.

The cloth table texture is more simple than everybody thinks. It comes form a scanning of the real thing, ofcourse it doesn'te fit the scanner, so it only scanned a part and assembled the rest. It also features a detail map for extreme closeups so that you can see the seems of the cloth. Woods, marble and other are photos from real materials. They were worked so that they could be tiled. Detail mapping helped alot with the "reality" effect. Even with real shadowing, subttle effects are hard to reproduce, so a small white and black texture created a darker upper wall and brighter lower.

The woods on the furniture use the same principle, first aply the tile closest to the real thing, them with detail maps "shape" the natural dark and bright areas, normally underneath a chair ou sofa is darker than the upper part.

Anyway, the effect is subttle but effective, without the realtime lighting it wouldnt work anyway :)

Thats that, we will post the demo online soon enough

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