A handful of random questions about texturing and types of maps
polycounter lvl 12
Sorry for all the threads about texturing lately but my google searches couldn't give me the answers I was looking for. I appreciate the help as always 
1) General Spec Map. Is there a guide or reference for how specular a material should be? I know the metals are more white in your spec map, and cloth tends to be more black, but what about everything in between? Is there a quick reference guide that can give me a rough idea of what value common materials should be so I can get an idea? Or does this all come through experience?
2) Luminosity map. I am working on a little lantern that I want to emit light with a luminosity map which shouldn't be to difficult to create. However I was wondering how this will effect the spec map in that area. Should the glass area that is emitting light also be effected by the spec map, or should the spec map be black in that area?
3) Normal map + opacity mask. I am also working on a window with glass and wanted to give it some cracks and nice detail. I was just wondering the normal map will still work for this even with an opacity mask combined with it? Do I have to do anything special with the normal map for that to work?
Any help would be much appreciated.
1) General Spec Map. Is there a guide or reference for how specular a material should be? I know the metals are more white in your spec map, and cloth tends to be more black, but what about everything in between? Is there a quick reference guide that can give me a rough idea of what value common materials should be so I can get an idea? Or does this all come through experience?
2) Luminosity map. I am working on a little lantern that I want to emit light with a luminosity map which shouldn't be to difficult to create. However I was wondering how this will effect the spec map in that area. Should the glass area that is emitting light also be effected by the spec map, or should the spec map be black in that area?
3) Normal map + opacity mask. I am also working on a window with glass and wanted to give it some cracks and nice detail. I was just wondering the normal map will still work for this even with an opacity mask combined with it? Do I have to do anything special with the normal map for that to work?
Any help would be much appreciated.
Replies
If it helps at all, here's what I tend to do (on a scale of 0 = black, 1 = white)
0 to .1 = skin, cotton, worn leather, etc
.1 to .3 = very dull metals, spots of wetness in cloth, dry paint, most other materials
.3 to .8 = most metals, some plastics, some glass
.8 to 1 = chrome, shiny glass, anything that I want to look very wet
Of course the ultimate rule is 'make it look good'.
2) I would say make the glass specular. The only issue you might run into is if light is shining onto that glass, the specular highlight + the emissive will be super blown-out. That's not necessarily incorrect, though. If it winds up looking off you can always change it, of course.
3) The normal map will show up as long as the window is visible (ie not completely transparent) and has specularity. Something that I've found improves the look of clean (not dirty/dusty) glass is if you set it's blend mode to additive, then make the diffuse dark (close to black) and the specular bright.
Well I would normally do that but this is for a class project that I need to have a 1080p render of using mental ray with a minimum 3 light set up. I use the real time viewport shader to quickly get an idea of what it is going to look like at the moment. Unfortunately I do need to find a way to get a decent shader setup for mental ray to render out an image.
Well I go to a school that is more geared towards film production pipeline, which is fine because the fundamentals are the same. I have to meet the requirements of the project even if it is a game resolution environment.
Had to comment on this, since I'm currently a grad student a school that also focuses on film production.
You're right that the fundamentals are the same. Fundamentals like shape, value, lighting, contrast, form, timing, stretch and squash, etc. The problem is EXECUTING these fundamentals in video games is very different from in film. I see a TON of students entering our video game production classes (or worse, working on research grants that use real-time engines) without any idea how to make things correctly for video games. Making models that only look correct when subdivided, thinking they can use maya dynamics inside udk, etc.
You're already doing better than 80% of the students I see, since you're posting on polycount. Just remember that if your classes don't teach you proper video game techniques, you need to spend time learning that on your own.
Just a pet peeve of mine. I don't even know how many time's I've had to teach another student something that they need to know, but never learned in class or took the time to learn themselves.
Yea for sure. I work on my own all the time to learn as much as I can for video game asset production. I know a good amount about about UDK, more so than almost everybody at my school. Next semester we have a environment art class that I help get started that is taught by a guy who has industry experience. I feel like I am heading in the right direction considering I have only been at 3D modeling for a little over a year.