Join Uli Staiger for an in-depth discussion in this video Creating a bump map, part of Digital Painting in Photoshop: Skytrain.
The train looks very, very shiny. It looks almost a little bit too clean, too shiny. If you zoom in, you can see that it is almost too perfect. So we have to destroy this impression a little bit just by weakening it. Of course, we could just reduce the reflection. But this still would make the surface shiny. So I think of another way. And I would like to add a so called Bump Map. The Bump Map channel you find here. And in order to work with a Bump Map channel, we first have to create one. We don't have one yet, so we have to create a new texture, and 1000 by 1000 pixels is fine.
It depends of course on your image. This is 2500 by 1450, so 1000 by 1000 is a good average. If your image is bigger, you can take a bigger bump map, if it's smaller, 500 by 500 should do it. You just have to try, you can't never say before if this is good or not so. You have to just try it. Okay, so 1000 by 1000. I say okay. And if I want to work with it now, because it's there. You can see the folder is white, not grey anymore. If we want to work with it now, we have to open it.
Open Texture. Here it is. And now we can work with this texture, and create the Bump Map. In order to create a Bump Map, it's just noise I want to add. And to add noise I first fill, with 50% grey. Then I convert for Smart filters because at the Bump Map channel understands Smart filters which is really, really wonderful. And now I can just add the noise. Filter>Noise >Add Noise.
This is what PhotoShop gives us, 12.5%, which is okay. We can try with that, we can make it a little bit stronger, but also, we can make the Bump Map channel stronger. So we just stick to the 12.5%. Uniform or Gaussian, it's up to you. This is a little bit stronger, it seems to be a little bit stronger, so I stick to a Uniform. the monochromatic doesn't have to be enabled. But if you do so, it's okay because only the luminance is going to be important for the Bump Map channel. So we add that noise, and looking at it, it's pretty hard. It's not soft, it's hard.
It would not produce a nice Bump Map, so we should blur this a little bit. Just add a new filter, the Blur filter> Gaussian Blur. 250 is a little bit too much, so something like between two and four still makes the noise visible. And you can still see that it's blurred a little bit. Fine, 3.2 is okay. Now we can close it. Of course, you want to save it.
And now you can see how the Bump Map works on this train. We have a Bump Map of one, and let's just see what happens if we go to a Bump Map of, let's say 4.8. It's probably too strong, but you see what happens. And if I go to a Bump Map lets see, 0.4 its okay too this would be zero. This is what we don't want and a Bump Map of many one is not too bad, we can use this.
Now if you want to make the noise bigger then we just reopen it. Open Texture, go to the Gaussian blur again, go from three pixels to something like 4.95 pixels. Close it again, save it of course. Now this is little bit smoother, and maybe we can switch from one to 1.5 . That looks more what I thought it should look. This way, you always can create a Bump Map to break up too clean structures.
- Creating the background
- Adding the train
- Working with materials
- Adding lights
- Finishing the project