Sun Aug 28, 2005 3:31 am
Nomad Textures - How They Work
Yes, I have gotten around to this 
Okie doke... here's how they work, folks. It's actually really simple:
1. A normal OcOtDcDt texture is applied to a surface or surfaces.
2. The nomadfx.txm file is applied to the ship, affecting both alpha and color channels, depending on the POV. It's basically being projected onto the object, alpha and all.
Basically, what makes Nomad textures work is that an alpha-channel TGA is being projected onto the surfaces for each frame of rendering. It doesn't matter whether or not the textures underneath them are clear or not- I've tested this out, and it really doesn't matter a whit. Setting nomad = true in the shiparch.ini entry and setting nomadfx.txm as the Material does the trick. You can play around with the color and Ec alphas to do various interesting things as well. I was very quickly able to create various colors of Nomad (pink, anyone?), and also end up with more/less visible ones... and I also quickly ran into problems with the fact that... because of the way that these objects are rendered, there are a lot've visual options that just don't work. Personally, if I'd been DA, I'd have done more work with solids, glowmaps... and then used this effect. I may even get down in the dirt and prove the concept at some point.
Which led me down several other paths... I thought I'd share some of the results of my whacky experiments yesterday afternoon:
1. I think I might have figured out how to make multiple highlight colors. This is of limited usefulness- a red highlight's going to look really dumb if your ship is an even mix of red and green. Still, it appears to be possible to do so- I was kind've surprised, honestly- I didn't think it would work. But you can set up TXMs with the CUBE instruction, and so long as the texture's a DDS cubemap, they work.
2. There may be some other uses here, for subtle shading for transparent objects. Like most of the other Alchemy tricks... this was basically a way to fake a lot of the things that are done on a per-facet/per-pixel basis in modern games with shaders. It's a fairly complicated way of going about things from a design POV, but it renders much more quickly than shaders, which weren't supported by most video cards when FL came out anyhow.
Okie doke... here's how they work, folks. It's actually really simple:
1. A normal OcOtDcDt texture is applied to a surface or surfaces.
2. The nomadfx.txm file is applied to the ship, affecting both alpha and color channels, depending on the POV. It's basically being projected onto the object, alpha and all.
Basically, what makes Nomad textures work is that an alpha-channel TGA is being projected onto the surfaces for each frame of rendering. It doesn't matter whether or not the textures underneath them are clear or not- I've tested this out, and it really doesn't matter a whit. Setting nomad = true in the shiparch.ini entry and setting nomadfx.txm as the Material does the trick. You can play around with the color and Ec alphas to do various interesting things as well. I was very quickly able to create various colors of Nomad (pink, anyone?), and also end up with more/less visible ones... and I also quickly ran into problems with the fact that... because of the way that these objects are rendered, there are a lot've visual options that just don't work. Personally, if I'd been DA, I'd have done more work with solids, glowmaps... and then used this effect. I may even get down in the dirt and prove the concept at some point.
Which led me down several other paths... I thought I'd share some of the results of my whacky experiments yesterday afternoon:
1. I think I might have figured out how to make multiple highlight colors. This is of limited usefulness- a red highlight's going to look really dumb if your ship is an even mix of red and green. Still, it appears to be possible to do so- I was kind've surprised, honestly- I didn't think it would work. But you can set up TXMs with the CUBE instruction, and so long as the texture's a DDS cubemap, they work.
2. There may be some other uses here, for subtle shading for transparent objects. Like most of the other Alchemy tricks... this was basically a way to fake a lot of the things that are done on a per-facet/per-pixel basis in modern games with shaders. It's a fairly complicated way of going about things from a design POV, but it renders much more quickly than shaders, which weren't supported by most video cards when FL came out anyhow.
