BY POPULAR DEMAND: Bump Map Tutorial

[Xhris]

Here's an animation of the light source being altered in some unspecific way.

[joroho]

Thanks, Xhris.

So does this mean we'll be able to achieve the same level of lighting effects that are done so wonderfully in RealDraw Pro?

.joroho.

[mikeengles]

Hello

"The merge function works as it should (see top pic), and is perfect with a photograph. The default intensity for the bump map is such that the greyscale bump map can be seen, but when merged with the image, is consequently bright. This is bump mapping; there is no distinction in "multiply" and "merge" processes. The bump map isn't overlaid; the bitmap is reprocessed at the pixel level."

I have to say that it does not work correctly. You should be able to merge the two, without overbrightness. Photoshop has a light intensity as well as a exposure to get the balance right

The only way to make the merged image correct is to reduce the intensity of the light to a point when the bump map is invisible, the light is black.

This is what I get with a photographs, that are correctly exposed.

Mike Engles

[Xhris]

What effect are you trying to achieve? Bump mapping is supposed to simulate the appearance of depth on a flat textured surface by adding light to the edges of 'higher' parts and darkness to 'lower' parts. If the effect you are trying to produce isn’t to give the illusion of mild surface depth of that texture as a result of the presence of a light source, then you may not be using the bump map feature for its intended purpose, and thus not achieving the results you desire.

If you’re just trying to increase the brightness of a photo, or globally alter some other light parameter e.g. contrast, then you should not be using the bump map feature. Use the bump map feature if you want to map bumps to a surface.

[Xhris]

Thanks, Xhris.

So does this mean we'll be able to achieve the same level of lighting effects that are done so wonderfully in RealDraw Pro?

.joroho.

I've never used RealDraw Pro. You will have to demonstrate what you mean.

[doane]

I just upgraded from X1 and am looking forward to getting my CD!
I haven't even had a chance to play with a lot of these new features in Xtreme, but saw this thread this morning and just wanted to comment, or ask a question. I thought bump maps were used with 3d programs, like in game tiles, etc. It looks like Xtreme can easily produce the bumpmap needed for this. Isn't most of what you are trying to do is producing what would normally be called emboss or extrude effects, not bump maps used for 3d?
Thanks,

[covoxer]

Hi Doane,

Ok, since you know how does bump map work in 3D programs and games, let me explain how is it related to BumpMap tool in XPE, Ok.

First of all, lets introduce some definitions, ok? Good.

3D Bump Map Effect - is the visual effect that modifies texture image based on the light sources and it's bumpmap data. Bumpmap data is much like grayscale image where every pixel's value represents it's elevation from the texture surface.

Emboss - is the visual effect that makes image look like it is engraved on the gray surface. It is relatively simple effect that is widely used in 2D raster graphics.

As you see these things have some common sense. But that's not the end.

So, in 3D software, this effect is made using separate bump map. And one of the fastest/simplest algorithms for that is based on Emboss. It just Ebmosses bump map with the light source direction and then combines it with original texture.

3D BumpMap tool in XPE is a bit different. It just does not use separate bump map. The bump map is built based on the original image. Simply making it greyscale. All other steps are same. Though you may control such things as number of lights, their type and you may not combine Embossed bump map with source image. In that case you'll get very advanced version of Emboss effect.

I hope it helps.

[doane]

Thanks for the explination John.
I've used emboss in Photoshop and it allows one to vary the light angle, intensity and emboss depth, directly to the image (no separate bump map image like in 3d programs). That embossed image can then be used under a layer to create a textured surface; is this not the same thing Xtreme is doing, or am I still not understanding?
Here's an example:
Image 1-2 is the original image on the left which is used to create a layer 2
the image on it's right is the bottom layer with an imboss applied to it.
image 3 is the layer 2 set to soft light

Image 3 is the final result after the two layers are flattned. It is the original image with the emboss effect showing through it using soft light filter.

[covoxer]

Yes, roughly it is the same thing you are doing in PS in this example.**
As I say, Emboss is used as a method to implement bumps lightening to the image. You go the same way in this example. Like following my description from the previous post

But you get all that in one interactive tool and you have much more options for lights settings in XPE, like the point or spot light, light color, 3D of the light source (X, Y and Z coordinates), and many more.

That's it, you've got the point.

BTW, there's a thing that I would improve in your PS example. You should create Embossed version of the image from the grayscale version. In PS Emboss effect uses simple convolution for all RGB channels an so you can see color shifts in the resulting Emboss image made from color image. If you consider using Embossed image as a lightening mask, it should be perfectly grayscale. So you have to add one more step: make a greyscale copy of the image before making it's embossed version.

[AKHTARAMIN]

Hope u like it