I’m relatively new to Blender and this is my first post, but I already have a question. After following a BlenderGuru tutorial called “Introduction to PBR Materials,” I made a Dielectric shader of my own, as shown below.
As you can see, it looks like there are bumps on the image, but as I zoom up, the surface seems flat. Are the bumps supposed to be visible when I’m looking at it from such an angle? Another tutorial I recently watched has led me to believe that I should be seeing the bumps when I’m zoomed in so much, but the surface seems smooth when I do so, as shown below.
I realize that this is a bad example, but my real problem was that when I used the same material on a plane after I appended the node tree and zoomed in, it seemed completely flat. However, you can see that at the crack, there seems to be no real bump. Could someone help me?
I assume you are using a normal map texture to give the bumpy surface. This does not actually change the mesh geometry, it just fakes the look of detail but the silhouette of the object does not actually change from the original object. If you want ‘real’ bumps you’d need to use a displacement map and a higher resolution mesh
Bump and Normal maps just tell to the render engine to simulate the behaviour of light over a surface with that bump map.
In poor words the render engine creates only highlights and shadows details generated by the interaction between the light and a surface that is only supposed to have the bumps you’re giving to it by the map.
It’s just a smart trick to save unnecessary geometry when not needed.
To go more far, if you want real displacement of your mesh, add a displacement modifier to your object and use your bump map as displacement texture and change the hight parameter. But the normal method is to use a displacement Texture to this!
Good Luck.
Thank you all for helping me! What you guys are saying is that the normal map just changes how the light reflects, and that I need a displace modifier for real bumps, right?
Thank you all for your quick response! What you guys are saying is that Normal Maps only effect how the light reflects off, and I shouldn’t be able to see the bumps unless I’ve used a displace modifier, right? Also, would a displace modifier make it any more realistic?
Yes displacement modifier makes it look more realistic, ( actually it the bumps are now real geometrie, so it is real). but you need to subdivide your mesh a lot, otherwise you see other artifacts.
So it could take a lot of memory. So use that only when need. For example things close to the camera.
There is something like parallax occlusion. The effect is a bit better than bump-, or normal-maps, but still at grazing angle you’ll see that the surface is flat.
Another option is to download the blender micro displament build. It is still beta I believe. You can download it at graphicall.org
Also here, depending on the settings, you need quite some memory. ( these builds seems to like to crash frequently for now).
