Good evening everyone. I've wondered a few times about bump maps, and decided to just go ahead and ask the experts about them.
I guess I'm not sure what they are; I mean, I know how to use them, but how are they made? Are they actually 3 dimensional, or does the use of light and shade just give the illusion of 3 dimensionality to a 2D image?
Case in point; I want to make an image of Batman, as he's portrayed in the movies - wearing body armor. Now, I don't have any body armor that I can apply to him, as I would clothing. But I'm wondering if I could create the illusion of body armor, with it's bumps, lines, crevices, etc, in Paint Shop Pro and just apply it as a bump map, and adjust the depth of the bumps, etc with the bump map dial in the material room.
Anyone who's "in the know" on this, please get back to me when you get a chance. I'm very interested in finding out more.

To put it simply, bumb maps are created to give a raised texture to the texture map.  They are usually grey in color.  Does that help?  Sharen

A bump map is a greyscale image in which black is down, white is up and grey is somewhere in between.  A good starting point for bump depth (in P6) is 0.00095.  If that's not deep enough, work your way up to bigger numbers.  Displacement can be useful, too but be careful because it can have weird effects if your value is high.  

Yes, you can simulate the appearance of body armour with a second skin and bump maps; I have done this to - IMO - good effect on occasion.  In fact, some of my own products use Hi Res bump maps to put a lot of surface detail in the texture.

Any more advice you need, please don't hesitate to IM me.  If you're a Batman fan, you're OK by me.

looks ok though

Looks very good indeed.  That looks very much like the Tim Burton Mk 1 Batman costume.  Nice work.

Black is not down. Black is no change. Gray 50% means 50% of the bump value in the numeric parameter. 

If you attach a completely solid gray bump map to a figure's face, the creases "cross" over each other and you get black splotches.

To get "down" you must use negative values. How to get that from an image? Subtract .5 from the image using a math node.

Acadia needs to make a collection of these threads regarding bump and displacement.

Masking into the Dissplacement Node?

what color is neutral grey for bumps...?

Mysterious Ink Stains!

Whilst we're on the subject of bumps... one thing I've often found distractin on the older models is trying to translate the gradient bump value to a similar approximation in the bump channel. does anyone know what the '1' level in gradient bump approximates to on the bump and displacement channels? I know it's now '1', because that grotesquely exaggerates the effect... any help here would be most usueful...

JonTheCelt

Quote - Black is not down. Black is no change. Gray 50% means 50% of the bump value in the numeric parameter. 

If you attach a completely solid gray bump map to a figure's face, the creases "cross" over each other and you get black splotches.

To get "down" you must use negative values. How to get that from an image? Subtract .5 from the image using a math node.

Acadia needs to make a collection of these threads regarding bump and displacement.

Masking into the Dissplacement Node?

what color is neutral grey for bumps...?

Mysterious Ink Stains!

Sho nuff, I phrased it bady.  I should have said white is the highest value and left it at that. :)

jon,

To the best of my knowledge, the Gradient_Bump channel on the root node implements "normal mapping". Unlike a bump map, which is one dimensional (gray scale), a normal map uses three separate channels (red, green and blue) of an image to describe perturbation of the normal, or even to describe the actual normal to use instead of the normal calculated from the geometry. I'm not sure precisely which Poser does.

You can read a good intro to what normal mapping is here.

I was in a thread once where the original poster was exporting a normal map (vector map, not a bump map) from some other tool and it worked perfectly in the Gradient_Bump channel. I've searched and searched but can't find the thread.