2010-12-08, 01:02 AM
I found out a little bit about skies last night / and managed to tweak the first map of Trismegistus to great effect, though I still need to formalize a lot of the stuff I did.
A) The band/halo around the sky is because the sky background doesn't actually go all the way up to the top.... the top is capped off with either the fog colour or some fixed background colour (probably fixed) ... it might definitely be interesting to use the fog colour instead as some kind of extension, though Ex doesn't yet have a per map framework in the .ini file it's definitely doable since Ex does know what map is loaded. Actually there must be three parts I'm thinking, because I don't know otherwise how the cap is rendered. The halo seems to get blended over.
B) All parts are in the .mdo file, and I only see two textures. Which means the cap must be a solid colour defined somewhere. Complicates preparing a .mdo file anyway a little.
C) The band/halo not blending seems to not be intentional. It happens because colorkey knocks out the top row of pixels which should be blended instead, but they fall below the knockout level (less than 8,8,8)
I can fix it by adding a colorkey disable fix to the images key, but I want to see if there is not a more systemic reason for this. I think anyway the dev team did not intend for the colorkey to be interpreted the way it actually is. They only specify to knockout 0,0,0 but for 15bit textures that's <8,8.8 ... so I wanna see if maybe the sky textures are 24bit and if so whether or not they are in both 16bpp and 32bpp mode. If possible it may help to distinguish between the two types and apply colorkey differently. If the textures drop down to 15bit in 16bpp however the only way to know for sure is to track the texture through the GDI interfaces where the colour conversion likely occurs. Anyway, if things go well it may offer a fix for holes in some files like the Triple Fang. There's probably a good chance though more files previously without probs would start sprouting black pixels where they don't belong, but anyway... it's worth investigating. It may also be I that I should be tracking the colorkeyenable state... but it's caused probs in the past. It may be it's only supposed to apply to textures and not blit operations. Will have to revisit that as well.
D) Raising the resolution of the sky will definitely help I think, but it dawned on me the unique way the sky swims like a flame might be lost with a higher res model... so I wonder if the design was intentional. Still I think a higher res sky would on the whole be better, and might just make the swimming more subtle. It may even be possible the animation code has the swimming built in, but I more suspect it's just a side effect of linear interpolating the texture versus spherical interpolation. You could also probably jitter the sky vertices a little to give them some more swirls. Kind of reminds me of the animated water in the opening area of KF2.
E) Bumping the mist texture up to 512x512 (by making a 2x2 quilt) really made a difference in terms of a polished feel. It probably seems to move faster. But let's be honest, the skies are more like an etheral snow globe than a real sky of any type. It definitely seems to work with Trismegistus to create a haunting / lush environment, and it felt good to see everything just so for the first time.
A) The band/halo around the sky is because the sky background doesn't actually go all the way up to the top.... the top is capped off with either the fog colour or some fixed background colour (probably fixed) ... it might definitely be interesting to use the fog colour instead as some kind of extension, though Ex doesn't yet have a per map framework in the .ini file it's definitely doable since Ex does know what map is loaded. Actually there must be three parts I'm thinking, because I don't know otherwise how the cap is rendered. The halo seems to get blended over.
B) All parts are in the .mdo file, and I only see two textures. Which means the cap must be a solid colour defined somewhere. Complicates preparing a .mdo file anyway a little.
C) The band/halo not blending seems to not be intentional. It happens because colorkey knocks out the top row of pixels which should be blended instead, but they fall below the knockout level (less than 8,8,8)
I can fix it by adding a colorkey disable fix to the images key, but I want to see if there is not a more systemic reason for this. I think anyway the dev team did not intend for the colorkey to be interpreted the way it actually is. They only specify to knockout 0,0,0 but for 15bit textures that's <8,8.8 ... so I wanna see if maybe the sky textures are 24bit and if so whether or not they are in both 16bpp and 32bpp mode. If possible it may help to distinguish between the two types and apply colorkey differently. If the textures drop down to 15bit in 16bpp however the only way to know for sure is to track the texture through the GDI interfaces where the colour conversion likely occurs. Anyway, if things go well it may offer a fix for holes in some files like the Triple Fang. There's probably a good chance though more files previously without probs would start sprouting black pixels where they don't belong, but anyway... it's worth investigating. It may also be I that I should be tracking the colorkeyenable state... but it's caused probs in the past. It may be it's only supposed to apply to textures and not blit operations. Will have to revisit that as well.
D) Raising the resolution of the sky will definitely help I think, but it dawned on me the unique way the sky swims like a flame might be lost with a higher res model... so I wonder if the design was intentional. Still I think a higher res sky would on the whole be better, and might just make the swimming more subtle. It may even be possible the animation code has the swimming built in, but I more suspect it's just a side effect of linear interpolating the texture versus spherical interpolation. You could also probably jitter the sky vertices a little to give them some more swirls. Kind of reminds me of the animated water in the opening area of KF2.
E) Bumping the mist texture up to 512x512 (by making a 2x2 quilt) really made a difference in terms of a polished feel. It probably seems to move faster. But let's be honest, the skies are more like an etheral snow globe than a real sky of any type. It definitely seems to work with Trismegistus to create a haunting / lush environment, and it felt good to see everything just so for the first time.