Why did you use LightWave for these lightmaps?

LightWave offers cutting edge technology for rendering. Its radiosity engine is very flexible and the fact that you can "bake" it gives you all the rich look of a radiosity scene in a texture. Surface Baker is an excellent feature. Other packages have the same functionality but Surface Baker offers more control over this special kind of "back-rendering".

For instance you can choose the UVMap to bake and decide to bake individual channels or the whole lot using the Map you want. And this is vital for a game-artist.

Choosing LightWave saved us a lot of time because it already had all the functionality we needed, just how we needed it. It’s also very easy to integrate LightWave in a workflow together with other packages and our own tools.

Aren’t LightMaps expensive in terms of console memory, though?

Yes, they are and we made things even worse for ourselves because we were using 24-bit coloured lightmaps instead of simple greyscale 8-bit ones... on a PS2!

The technical director Francesco Iorio and I developed a technique that not only reduces a lightmap's size in memory without using any hardware compression system, but also keeps all the color range of a LightWave radiosity render.

We achieved our technique thanks to LightWave's support of HDR data. It would have been impossible to develop this technique using normal 24-bit images.

Why not use 8-bit lightmaps instead of the 24-bit ones?

I wanted to use 24-bit lightmaps for their colour range. If you notice, other games use 8-bit greyscale lightmaps because they don't occupy much ram and the depth is enough for a smooth "shade", but if you want colours in your lightmaps (especially using radiosity) you also have to have enough depth in order to "mix" them with the color textures.

We can use some lightmaps as 8-bit indexed colour textures, but most of the time the range of colors in a lightmap is too wide to look good when converted to just 256 colours.

Also, you usually only have a resolution of 30 or 25 pixels for each square meter. Sometimes even less. If you have a 8-bit coloured lightmap you'll probably have dither or poor shading that will be magnified when applied to your geometry. You’re bound to notice blotches because of dithering or stripes because of poor shading. The effect on screen of our 24-bit lightmap system is just like a radiosity rendering with less resolution but at 60 frames per second!

We're using quite low-res lightmaps at the moment. On average, the size for each lightmap in the screenshots with this article is just 128 x 128 pixels. The final lightmap resolution will depend very much on the different consoles that run the game. I think some versions of the game will have lightmaps that are twice or even four times bigger (256 x 256 or 512 x 512) — this will make a huge difference!

Aside from Broken Sword 3, you’re also quite a busy chap with LightWave, aren’t you?

Well, let's just say that I'm honoured to be part of a team of incredibly talented artists and programmers involved in the beta program for LightWave and I also write plug-ins and LScripts, including a quite well-known package called AnimPlus, the main part of which is a script called DynaParent that offers much of the flexibility of Messiah in LightWave itself.

Is the DynaParent plug-in used by anyone in particular?

Yes, EdenFX, the guys behind the special effects for Enterprise are using it. Thanks to Fred Pienkos at EdenFX for his suggestions and his precious time.

You can download the AnimPlus plug-ins at http://www.forwardgames.com

Excellent. Thanks for your time Emanuele!

Thank you!