How to create a bump map?

deleted user

I'm having a very hard time figuring out how bump maps are made. Espeaccly with skin. The skin for example. If I gray scale the image. The eye brows are black, instead of white... How on Earth do people create bump maps? What program are they using, and it's not shademaper I'll tell you that much. Shademaper is just as much guess work as gray scaling an image and hoping for the best. Like walls, floors, bricks, skin.. they all have bump maps. But I don't know how their made....

nonesuch00

After you greyscale it I think you have to reverse the map - like a film negative.

Then you could use a software like Terragen to increase or decrease the 'height of the bumps' although I've never tried that but technically it amounts to the same thing. Not sure though if you can save it back out as a usable TIF but I'm betting you can.

Personally, I prefer Terresculptor Pro. I don't know when it's going to be considered finished though. The man making that SW though knows what he is doing.

 

nonesuch00

Here is the link:

http://www.lilchips.com/hmesbeta.htm

Don't laugh to hard at me for suggesting a landscape creation SW for editing your bump maps.

Richard Haseltine

Ideally the bump map is build along with the other channels, using whatever tools the rest of the componenets use. Failing that, workling from a map that is consistent (the skin without details such as moles, brows and so on) to get a base with the right kind of frequency of noise and hopefull something semi-plausible for height, or making up a geenric bump from patterns of about the right frequency, and then adding in the extra details to both diffuse and bump maps. Tools like Crazy Bump and Bitmap 2 material may be useful, though I've had limited success in trying to generate a good (to my taste) bump map from texture files. If you are starting from a finished texture that lacks bump maps you are going to have only limited options.

deleted user

Basicly I have what amounts to generic outcomes with photoshop + shademaper. One thing that might be helpful is if there was a invert brush for photoshop. Some parts of the bump need to remain gray scale, like knucles, wrinkles and acne scars. while others, like brows, pubic and facial hair, and nipples need to be inverted. Simply gray scaling a skin creates all sorts of anatomically incorrect problems.

nonesuch00

Angel - Wings said:

Basicly I have what amounts to generic outcomes with photoshop + shademaper. One thing that might be helpful is if there was a invert brush for photoshop. Some parts of the bump need to remain gray scale, like knucles, wrinkles and acne scars. while others, like brows, pubic and facial hair, and nipples need to be inverted. Simply gray scaling a skin creates all sorts of anatomically incorrect problems.

Well if you are lucky enough that all the 'hair type greyscale ranges' is outside the entire range of 'normal skin type grey scale ranges' then any tool that will let you select the entire range of 'normal hair type grey scale ranges' and invert the values. There is the select by 'value' that only selects by value plus adjustable boundary cases in Gimp & PS and you just keep ctl pressed with you mouse select to add to the selection. It will be tedious & you'll need a steady hand.

I know Terresculptor Pro can do that and I'd be really surprised if the tools Richard mentioned can't do similarly but have it made easier for you since they know you are trying to create a bump map to begin with. 

deleted user

I'll try that and see, thanks.

deleted user

For now it seemed to have solved some of the discrepancies. The issue I face with my skins is that I almost never use a stock out f the box skin. I've been editing skin mats for 4 years now I know I shouldn't have to ask how to create bump maps by now but I'm a hands on learner and never popped the question. I've always just manually painted the inverse... I learned one new thing in the proccess. If you dodge and then burn the lips. It gives the lips a lot more volume and detail to play with. Making them look more like lips, and less like a barbie doll plastic.

Roman_K2

Don't forget, you may also need to adjust the BUMP factor for a given skin or modified bump map, in the Surfaces pane. And if you resize a large render some of this detail may get assimilated. Also, you don't HAVE to have your entire figure bumped up (or down)... you can make a copy layer in an image editor and then cut away most of the bumped area using a soft lasso setting... for example you may leave a few skin irregularities in places that are closest to the viewer.

For what it's worth, I've had mixed results as far as the skin goes when rendering V4/M4 and G, G2, and G3 figures, but I usually try to crank up the bump factor a bit. My main issue so far is an occasional "pasty" or "plaster" look in stock skins, and bumps for the sake of bumps (or so it seems). Lips on G2 and G3F seem to be better but I wonder if that's because sub-surface scattering is supported? To me -- and I may be wrong -- SSS seems to add more detail to the play of light on a glossy or wet surface. I do wish I knew how to play with the physics!

Here's a related thread from last year - http://www.daz3d.com/forums/discussion/63562/bump-map

Wikipedia English has articles on bump and displacement mapping etc.

jestmart

You cannot make a proper bump map from the diffuse texture, when will people get this.