have some procedural questions about spec maps and normal maps. First of all, spec maps: what's the best way of creating a specular map? What are some tips and tricks and what not that make great spec maps? I know what a specular map does, but i have seen many specular maps that i look at and not sure they look like they do. Poop has one for his skateboarder on his website that particular interests me.

And for normal maps: What's the best way to get your spec map to really bring out that normal map? What normal map generation program do most of you use? (i have been using max's projection mapping, but not too happy with the results. I tried using Melody, but I was getting strange results just trying to do a projection like in max)

and most importantly, what's the best way to paint your diffuse for your normal map? do you paint over the normal map? is there a better method?

Thanks for your time!

Jeremy

I like to generate a heightmap at the same time I generate a normal map, which I find works great as an overlay or multiply layer on top of the specular, so the specular doesn't show in the deep cracks. If the heightmap doesn't look good, I'll generate an ambient occlusion map (AO) instead.

I also like to multiply this on top of the diffuse map at 75% or less, depending. Adding a little AO is good, since real-time lighting usually doesn't include good AO (it is starting to be used though). Also provides a guide for color location.

Specular maps... I just try to think like shininess. [img]/images/graemlins/smile.gif[/img] Where would I be glossy, where not? If I am shiny, why am I? Wet? Smooth? Greasy? This helps me determine the color to use and where to put it.

I find it helps sometimes to use a hue for the specular that's 180º or 120º from my color map hue, but subdued. Adds richness because it tends to desaturate the color mmap underneath the specular highlight, which then causes the rest of the texture to look more saturated. That's why you'll see people using purple or blue for the flesh tone specular, because it's a kind of hack to get a sub-surface-scatter kind of look to the sides of the specular.

Pior has a great tutorial that includes how to generate a specular, though for me painting is generally better/faster.

Helps me to reinforce the specular with bump detail. I just did a Medeival stone wall with drippy green slime running over the stones... the normal map gives the slime a slightly-raised edge, the diffuse makes it a bit green, and the specular uses a light orangish color.

I find it's good to use a full range of value for every map... thresholding a map to solid-ish colors reduces the richness of the texture. Holds true for color maps, specular maps, AO maps, etc. Specular color maps in most engines need to be fairly dark, but within that range you'll get better results with variation, instead of just solid areas of color.

We had a good discussion about specular color and lighting awhile back, might be a good read. I used to use the nick "posm"...
http://dynamic.gamespy.com/~polycoun...130.html?00037


Whew. Typing this out is good for me, helps me think.

Hey animatr, I have some thoughts about creating specular maps here: http://www.3dm3.com/tutorials/maya/character/index6.php

Hey Daz, what's the reasoning behind painting the pores as bright dots? I'd think you would want the inverse... dark inside the pores, light on the rims all around them, so the specular stays outside. When I look closeup at my own face, the insides of the pores shine the least. (or maybe I just need a good scrubbing)

Well, I guess it depends how you visually read the image as to wether or not you see the white as dots. I kinda see it more as the black is breaking up the white. But I dunno. It's really whatever works that counts. Im sure you could come up with a much better representation of a skin pattern. I don't actually use this one anymore, but If I posted what I do use, I'd be giving it all away! [img]/images/graemlins/smile.gif[/img] This was about principles really, as opposed to the Art assets themselves.

wow. thanks for the great info guys and all for the awesome links. learned tons of stuff. Makes me want to go back and redo some of my older stuff thanks again! If anyone has anymore tips and tricks, spread the joy!

Hey Daz...do you know any way to make spec maps show up in real time, in Maya's high quality display mode? I can change a Blinn shader's specular roll off and eccentricity with the sliders and these changes will be shown fine, but as soon as I plug in a texture it no longer displays. Any thoughts?

Well Daz, the result turned out great. That's all that matters! Did you use any color in his spec map, or was it purely an intensity map?

On the same site as Daz's tutorial, there's also an old tutorial from J-J-J Mortimer. He has some info about specular color, though it looks like he used two maps as combo specular and reflection passes. Not much meat there in terms of info, but he did offer some nice large example images.
http://www.3dm3.com/tutorials/maya/texturing/index6.php

Hey CheeseOnToast, I wonder if you could adapt Ben Cloward's excellent HLSL shaders for use in Maya? He supports real-time specular, etc. They're written for use in Max, but I would imagine Maya would somehow support these shaders as well...
http://www.monitorstudios.com/bcloward/resources.html

Haha, I just reread my own line which explains a few things:

"Specular map 1 ) To be really clever here, we should probably use the same base texture pattern for skin colour base, skin bump and skin spec in terms of its patterning of skin pores. For some bizzare reason that I can't recall, I didn't in this case, but I think you'd have to be a pretty astute observer to notice. So starting from scratch, or from an existing base map you've made, create a pattern that looks somewhat like skin pores. "

That'll make you the astute observer then Eric ;-p

For skin I usually just use the stahlberg ramp method of tinting it blue to counteract the tendency for it to yellow when hi-lighted.

CheeseOnToast: the weird thing about that is, at work we use the high quality display mode for normal maps, and some of us can get it to work, and some of us cant. I personally cant, and I think it's due to an aging grafx card. But the ones that can get the normal map showing in the viewport fine, just slot the spec in the spec colour and it just works!

worthy to be sticky imo

Hahha Daz, not so astute if I didn't actually absorb your words the first time. Good tutorial, especially (for me) the image-reference section.

I still don't understand the yellow-tendency thing. Per had a good point, in that other thread:
-Specular is additive, and adding grey to anything retains the existing saturation.
-If you want less saturation in the highlights, the specular map needs to be the opposite colour of the diffuse.

I wonder if the yellowish highlight tint is because the skin color is (for caucasians) mostly tan already, and the white light is simply brightening the colormap.

But when I look at a photo of someone in the sun (my son last summer), I don't see a yellow tendency.

What I see is the skin generally turning red right next to the light/shadow terminus, like under his cheeks and eyebrows. For me this is what makes skin come alive or not.

So, if I'm thinking correct, using a bluish specular color seems to help solely because it desaturates the lit side, allowing the terminus to be more saturated, simulating SSS.


I dunno, I'm still kind of confused about the colored specular thing. I'm thinking it mostly works this way because of our primitive lighting/rendering tools. I should probably have some 3D examples here instead of photos.

Well, I guess I took mr. Stahlbergs word for it without really questioning it. I think you're right in your assessment of how the principle came about. It was all born from his attempt at vague SSS in the maya software renderer, so the desaturation could well be an attempt to bring out the red near the terminus.
I've actually found that the blue-hi-lights thing works better in renders attempting to be outside, and I think that's because Im assuming that a very bright hi-light would be bouncing off a surface that is somewhat reflective and hence have some sky colour in it perhaps?

Yep, I think Daz is right about the blue thing - if a subject was indoors and lit differently, blue might not be the best choice - it seems to work best for outside renders because the sky tends to tint a lot of things bluish on a sunny day.

Well, that really depends on how blue you make it. Mainly the blue is to oppose the color of the skin so you get desaturated highlights. Helps you get away from the usual plastic-y look of cg.

OK that's what I thought. It seems to be a quickie to counteract our lack of rendering power. I see what you all are saying about the blue "northern light" part of outside lighting.

We have something in the pipe here that might help out with this, but it'll likely incur multiple passes. The idea is to dynamically generate a mask between two materials, based on the light angle (or others), with some additional controls for the gradient. Should be cool...

ok guys, my 2 pesetas, quickly
specular is reflection of strong light source(sun)
ambient light is reflection of global light(sky)
materials have different properties of reflection. Clay has wide and desaturated highlights. Smooth plastic has saturated and sharp highlights.

There's a lot to be said about the physics of light and the reflective properties of materials, maybe I should write a doc finally

oh, yes so the point: use blue in skin specular maps still indoors. there's no difference. The blue is there to describe the nature of the material, not the external light sources.
[edit]: EricChadwick, everything hit by sunlight in that photo is drenched in yellow, the grass, the trees, the skin. Shadowy areas are influenced mostly by the ambient sky color, like the house. Now check out the strong highlights on your sons skin, they're almost grey. Very desaturated.
The red skin in the shadowy areas is because you're not seeing light hitting skin directly there, but light as it has traveled through flesh and been stripped and now consists only of red wavelengths

http://www.itchy-animation.co.uk/tutorials/light01.htm

Set of tutorials talking about the properties of light. might be useful for some

Yeah, that's a good review Keg. Another here, from a painter's perspective. You've probably seen it.

Hmmm, Per I'll have to disagree with you that the sunlight is yellow in this shot. The shiny wet parts look white to me. I see some mild yellow edge-ringing around his right forearm, artifact of the sharpen filter. But for the life of me I can't see any yellow light, anywhere. [img]/images/graemlins/frown.gif[/img]

Would have helped if there was something like a neutral-white reference ball to judge the color balance.

I do agree though that the skin along the shadow edges is showing sub-surface scattering of the light, being filtered through the blood inside.

Not trying to argue for/against blue speculars, I'm just not seeing it reflected in the real world. I do see however that it does serve to make a more varied surface, since we're mixing complimentary colors. Also I need to stop writing and start doing more. [img]/images/graemlins/smile.gif[/img]

This is great information guys thanks.

Eric. woah, respect. I'l learm 3dsmax with your books.
Glad to see you here.

Thanks, man. Gotta say though that the knowledge pool is much wider around here than me, I've learned a ton more from the amazing people on this board.

And I've tried writing a book, well at least a chapter, and it wasn't really worth the effort, for me anyway. You can learn a lot from writing though, so I encourage others to give it a go. It's just not a money-making proposition, is all.

Specular is a monster, especially when coping with your normal. One thing to remember that ive been making sure ive paid attention to was that all details you put into your diffuse should, in some form or another, exist in all other textures.

You dont have to go ape shit and put noise all over your normal, but if there are major dark areas that are cracks or dings, it really helps to put this into your normal and specular maps. As for my process:

I will get a mesh, and all sorts of render files from Ror; a Normal Map, ambient occlusion map, lit render, lighting render, shadows render, color map, and height map. When texturing, i will generally maily use the occlusion, and lighting maps, set them to overlay / multiply at a light opacity to get the general form of the high poly baked into the diffuse (subtly).

From there i go to town on the diffuse, adding whatever it is that needs added. As i add major bits to the diffuse, i will go into the normal and get matching parts in it via the normal map filter in PS.

After chunking and detailing, ill build up the specular based on diffuse information, either completely taking areas of spec out, or really poping areas up so they shine. In order to get the most out of all 3 maps, you need to keep things consistent and flowing, so it doesn't look random.

For speculars, yes blues do work really well, and make some really pretty colors. However, you should think about what color your diffuse is, and what color you actually want the surface to be - since no one willsee your texture work in the dark, and light = specular. Ambient light will let you fill in the general colors, but when light hits it, there could actually be gold hidden under the grime. I try not to think about the technicalities of how light actually works (although ive read a bit to understand how it works and reflects light), and focus on "what looks the best?" If its blue, yay. If its gold, yahoo. Whatever is pretty [img]/images/graemlins/smile.gif[/img]

Nice. Glad to see your post here moose. What do you use these days for viewing/refreshing the combined result while you work? The game you're creating for, or another tool like Modo?