Proposal for Hardware T&L support Option

Short for Transform and Lighting, T&L is a type of video technology that takes all the 3D information that used to be handled by the computer processor and gives it to the GPU. This enables for a more complex 3D environment by adding a higher polygon count and improving the lighting at the same time it allows the computer processor to handle other tasks.

Er, how do you know hardware T&L ISN'T being used already?

I don't see how it can when stuff like Local Lighting, Shadows, and stuff like that where T&L should be doing its job is running like crap. And its been said 1000s of times that Local Lighting is processed by your CPU and not the GPU like it should be.

4. Light objects cause the most load on the client CPU, not the graphics card.

yea but it could cast a light source with little issue on a 500mhz computer

AW 3.2 introduced hardware lighting which has adverse affects on untextured polygons (not just flat-shaded--lightsampling facet--as the FAQ claims but also vertex lightsampled polygons), causing them to become much brighter (to the light's color) when a light source other than the global world light is shining on them (and somewhat brighter with just the global world light). It is extremely annoying because it means objects must be designed specifically for textures if they are to look correct at all times, and any untextured polygon on the object will appear brighter. Unfortunately there does not seem to be a workaround for this, and it may be a hardware/driver issue. However, I'm still looking into this--but it doesn't look promising, unfortunately...

Hardware "T&L" support

The term "T&L" refers to "transform and lighting." Transform and lighting are two computationally intense (in other words, slow) stages of the 3D rendering process that have traditionally been performed in software. However, the latest generation of 3D accelerated video cards (including the Geforce from Nvidia and the Radeon from ATI) can now perform these calculations directly in hardware, relieving the burden from the main system CPU. The Direct3D support in version 3.2 has been updated to take advantage of hardware T&L if it is available in the local 3D hardware. OpenGL mode can also use hardware T&L if your video card and drivers support it.

Q. Why do some of my lights look different now?

The basic lighting model used by RenderWare has changed in 3.2. The old (Active Worlds 3.1) lighting model was a simple software model where the intensity of the light declined, or "attenuated" linearly with the distance from the light, up to the light's maximum radius. The new version of RenderWare in Active Worlds 3.2 uses the new hardware lighting model available in DirectX7 and OpenGL, which is compatible with the hardware T&L (Transform and Lighting) acceleration available in newer video cards. In this new model, the old linear attenuation formula is gone, and it has been replaced with a more complex formula that includes constant, linear, as well as quadratic coefficients for controlling the attenuation of the light source. The end result of this new model is that it is not possible to exactly replicate the old lighting model of AW 3.1 in AW 3.2. Thus, although we've made every possible attempt to maintain consistant lighting behavior from 3.1 to 3.2, some lighting will look slightly different now.

There are other differences as well. One significant difference is that OpenGL does not support the concept of a maximum light radius. Thus, setting a radius on a light while under OpenGL has no effect, meaning that a radius-restriced light under Direct3D may wind up shining much further under OpenGL. It's a good idea to test your lighting under all three video modes (Direct3D, OpenGL, and software) to make sure it looks right in all cases.

Another issue is that the hardware lighting in DirectX7/OpenGL only supports a maximum of 8 lights at once. In AW, one of these is always taken up by the world's directional light source (the ambient light source is not really a light so it doesn't count) which leaves 7 for in-world lights. If a scene has more than 7 lights in effect, the extras will revert to a slower software light implementation, which often looks different than the hardware lights, and is also much slower. Thus, more than ever, for best performance it is a good idea to use light sources sparingly at all times.

One other issue is how the hardware lighting in DirectX7/OpenGL affects flat-shaded (i.e. non-textured) objects. Under the old (3.1) model, a light source, no matter how bright, could only affect the color of a flat-shaded polygon so much. Under 3.2, it seems that hardware lights can have a much more severe effect on flat-shaded polygons, to the point where they can be lit to a full-intensity white. This effect is occurring in hardware and there is not much that can be done about it from within AW. Fortunately, this effect does not seem to occur on textured polygons.