Bump vs Normal vs Displacement

Alright, thought I'd make a nice big informational post regarding the three key things that make your shader look nice and detailed. Unfortunately, bump, normal, and displacement maps tend to confuse people. To add to the confusion there are software developers who like to switch between the two terms displacement and bump in their software so be careful.

The three things here have one goal: to make things look realistic and each have their way of doing it. The reason why people get confused is because they all look like they do the same thing (excepting in the case between displacement and bump values, they're significantly different.) But each have significant differences between how they achieve a certain look or feel.

First of all the bump value. The bump value simulates lighting on a surface of a bumpy object. For example a surface of a rock is bumpy or a tree bark has a bumpy look. When you apply light to these objects, the light will get picked up in certain areas leaving other areas in shadow. So the basic idea of a bump map in a shader is to give the viewer a sense of depth by simulating the flow of light on a bumpy surface (given the grayscale map.) The unfortunate thing is that bump maps do not simulate actual depth in other words even if it LOOKS as though the object's surface has some form of bump, the geometry doesn't. So it's just a simulation of light passing over an object.

If your software allows for alternative slots for bump/normal and displacement maps. You can take advantage of that and generate further detailed looks and feels. In this case I threw in a bump map and displacement map. The shading is much more detailed (and maybe in this case too much) but the idea's to be able to adjust further detailing and give a bigger sense of realism.

Conclusion: I wrote this because people get confused between the three There's also the fact that SpaceRay made a post asking what software to use and otherwise so I was like... why not a thread regarding shaders.

But let me just summarize here: a bump map gives us values between zeros and ones (or sometimes certain softwares allow for HDR values) to simulate the sense of depth. A displacement map gives us again values between zeros and ones (or beyond) but gives us further detail by altering the geometry. A normal map does what bump maps do but a bit better. It stores data in RGB channels hence you can get more data out of one image. So just to make it super easy: a bump map gives you "intensity" values, a normal map gives you "directionality" values. Each of these have disadvantages and advantages over the other and can be used in combination for further detail on a given shader.

There are other types of maps which provide further extension of realism and gives us more control for example vector displacement maps, AO, rAO, Specularity, Metallic, SSAO, and otherwise. They have special purposes and share different parts of the shader tree providing us with further detail and control over our 3D scene.

Alright, I'm done messing with the forums. I'll transfer this over to my blog because it'll get buried in the forums anyway. Got questions: ask below!

Great explanation, easy to follow and understand.
Thanks alot for the detailed info, it's gonna be usefull for alot of 3D wannabe's like me.

One question, as you said, normal and bump maps each have their limitations, so if the software allows for it, one should use both. But since both affect how light reflects off of the surface, wouldn't there be a 'power struggle' between them?

Could you post three renders of the same object, using bump on one render, normal map on another, and a combination of both on the last?
It would be easier for me to see the different effect of each map, and under what circumstances each one does a better job.

Thanks!

I'm having a filter in the makings and I have a checkbox to set it into displacement mode, to generate dispalcementmap instead if texture map as the displacement I'm after should be much less noisy compared to the bumpmap. I'll post some renders in y thread when I have something to show what I'm after.

Skybase I want to thank you again for all this great and well done tutorial explaining all this in a good and useful way

Thanks to you also I know also how to make now displacement map inside FF and not only externally on Photoshop or in a 3D software

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Totte I'm having a filter in the makings and I have a checkbox to set it into displacement mode, to generate dispalcementmap instead if texture map as the displacement I'm after should be much less noisy compared to the bumpmap. I'll post some renders in this thread when I have something to show what I'm after

Have you done something with this? Sorry that I do not know what you want to do, but may seem interesting and useful.

I think that now that FF 9 supports PBR and the result component has been updagred to support 3D export for Unity and Unreal and other 3D software, this very useful and great information is even more useful and valuable

And I can add more options that are also available apart

3D texture mapping that will give a “Fake” geometry 3D relief aspect

https://filterforge.com/forum/read.php...&TID=15905