Illumination channel support

[Eric Cosky]

This was mentioned elsewhere on the forums but I didn't see one in the feature request, so here it is:

Support for an illumination channel that is a peer to the existing depth, color and specular channels in all functionality of 3DC including materials and exporting.

I'm sure it's asking a lot, but hopefully it can be considered because illumination channels are very useful.

Here is a link to a website that sells models (this isn't a plug; I have no relationship to these folks, they just have some cool models that demonstrate the feature request) - the page demonstrates illumination maps in practical use down at the bottom in an animated GIF: http://www.3drt.com/3dm/sf-naval/Sci-fi-naval-shots.htm

Thanks for reading-

[Jokermax]

is that a lightmap/baked lighting? you can just bake it into diffuse if needed

[Eric Cosky]

is that a lightmap/baked lighting? you can just bake it into diffuse if needed

Yes, it is similar to a light map but baking it in isn't a solution for objects in games that need to move around and be affected by lighting (baking it in would partly work for static geometry but only for fixed lighting environments). The diffuse map is affected by any lights active at run time, and (in my case) the illumination channel is rendered as a purely additive effect that is unaffected by scene lighting. So as time of day changes, for instance, the glow emitting from the illumination channel will remain visible at night but the diffuse channel will become black. Fires and evil glowing eyes stay visible even without lights in the scene. Or flickering lights

I wouldn't be surprised to hear that Andrew has thought about generalizing the channels to some day become general purpose shader texture channels where we would have as many or as few as the user desired, each with it's own user-defined texture resolution and bit depth (spec can be lower res sometimes, for instance) and mapped to a different CgFX/HLSL shader, but that's obviously a lot of work and perhaps when v4 features are being requested it would be worth bringing up again.

For now, I suspect that adding one more channel for illumination would be easier, bordering on possible to hope for in 3DC in the not too distant future (still a big chunk of work though) and would address one of the bigger needs of real time users such as myself. I frequently create a diffuse, specular, and illumination (emissive) maps as separate textures that are fed to different shaders and I don't yet know how to fully integrate 3DC into my work flow without support for an emissive channel. I can work around it, I think, but it would be nice to have available.

[Andrew Shpagin]

I will take it into account, but it is not so easy.

[Jokermax]

oh sorry i completely mixed up - you are talking about emissive/glow map. Yeah that would be handy

[Skaven252]

Here is the topic where this was polled and discussed before it was made into a feature request.

In that thread I suggested a simpler way to implement this that will not require an UI overhaul (as in, Luminosity would be an additional channel, requiring new buttons and sliders on the UI, and adding a Luminosity channel in all Layers). The other way to do it could be to give one of the texture Layers a new "Luminous" blend mode. Then anything brighter than black painted on the Luminous layer would glow in the dark. Implementing the feature this way would require much less changes in the UI, and - while I'm not a programmer, I suspect it would mean less overhead in resource usage as well, as not every layer needs to have a Luminous channel reserved.

[GED]

yeah emissive / self illumunation map would be nice but I have to say it doesnt actually have to glow or emit light. As long as its a map which displays its colours at full brightness even in shade then its probably good enough to estimate what it would look like in game.

[Eric Cosky]

yeah emissive / self illumunation map would be nice but I have to say it doesnt actually have to glow or emit light. As long as its a map which displays its colours at full brightness even in shade then its probably good enough to estimate what it would look like in game.

That's exactly what I meant to describe.

[Roger_K]

i doubt its the emmiting of light thats the issue, well so long as you dont want bounced light . You'd think that would just be another term in the shader. I'd say its down to the fact that 3DC is optimised for the current number of painting channels and adding more would be disruptive to this..only a guess but it would make sense

For the time being why not just paint your glows in a seperate layer? then just export them on their own.

[GED]

For the time being why not just paint your glows in a seperate layer? then just export them on their own.

yeah thats all thats really needed as long as you can set that layer to show with full brightness even in shadow? just to get a good idea of what your working with

[Roger_K]

yeah thats all thats really needed as long as you can set that layer to show with full brightness even in shadow? just to get a good idea of what your working with

bake an occlusion pass, go into unshaded mode and paint away

I've used unshaded for low poly (VERY Low) work and its very nice