Is it possible to use two different normal maps on one object?

I sculpted a high poly statue and then created a low poly version of it. I baked a normal map from the high poly onto the low poly model. I also want to use a texture map of a smooth stone and created a spec map and normal map for it. I set up a node tree for the texture map, spec and norm, but I can’t seem to add the other normal map without creating problems. The UVs for the texture map need to be scaled up so the texture is the right size and so I created a separate UV map for it. The UVs for the high poly normal map can’t change and so there is a UV map for that as well. On the Normal Map node there is a setting for the “UV Map for Tangent Space” and when I set it to the correct UV map for the texture it makes my material in the preview turn black. When I look at the model in render mode (I’m using Cycles) the texture looks too large like it’s using the wrong UV map. :confused: I would appreciate any help I can get, thanks!



You can use the attribute node to gain access to more than one UV layer.

Add an attribute node, type in the name of the UVmap, and make a connection from the purple output.

Looking at your setup, I also wouldn’t forget the fact that you can simply combine two normal maps together using a mix node rather than resorting to two shaders.

Thank you for the info about the Attribute node!

Right now I have a Mix Shader and an Add Shader, should I get rid of those and use a MixRGB node instead?

Yeah it’s probably faster for Cycles to mix the two normal maps with a mixrbg node first and then go into a normal map. And the image at the very top, the one you are using as a mix factor, you probably want ‘color data’ for that one. And a normal map with a strength of 10 seems high. And the add shader doesn’t seem right. Looks like it’s coming along nicely though.

Double post. :frowning:

Thank you very much for your suggestion! I’m having some difficulty understanding how to set up my node tree so that I can do what you suggested. I’m including my current node setup, would you mind looking it over and helping me fix it? Thanks!

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Okay, I tried to move things around a little, does this seem better?


I seriously doubt if simple color operation will give correct result if inputs are 2 different normalmaps.
You would probably need to separate RGB components of normalmaps and combine them later following what’s in this PS tutorial, or other method which give proper result.

Thanks for sharing that tutorial!

I tried out the sand material set-up that @blenderallday linked to. I think this looks much better than what I was trying to do with a texture, spec. and normal maps.


I’m not sure if I have the normal map hooked up in the right way.

You have done all correct what concerns adding normalmap part.
Only thing you might want to check is if Bump group and normalmap works well together. Disconnect temporarily (or M - mute) bump and visually check if it’s ok. Sometimes they tend to struggle with each other.
If it is sandstone you might want to decrease glossiness (if it is not a leaking water; i guess it’s not ;)). Try connecting IOR to Mix via ColorRamp node. Not sure, but right now it looks like shininess comes from front faces; guess you need it opposite way.

I think that sand material looks great. I agree with eppo that there is just a tiny bit to much gloss on it, that old sandstone loses it’s lustre over the years. Also I don’t think you are using any environmental lighting. If you haven’t (or anyone else) you really need to get yourself a few of these images. If a scene has any gloss in it you can increase it’s look and realism by adding an hdri (or jpeg) to it. This image is projected spherically around your scene and adds critical color information to the reflections, as well as acting to light the scene. The image below illustrates it much better. So get over to:
http://www.hdrlabs.com/sibl/archive.html
And download and unzip one of the image sets that best matches the lighting/colors of the scene where you envision this statue sitting. You don’t have to use the full resolution hdri for tests, each pack contains low res preview images, just switch it out for final renders. You must be in camera view to see the actual image. Now this example with suzanne is pretty drastic, she’s 100% glossywith 0.0 roughness ( a perfect mirror) on most of her. You sandstone won’t have such sharp reflections but it will increase it’s feel, and it’s a good club to have in the bag.


Thanks for the suggestions! Here is a screenshot where I muted the bump.


Here I muted the normal map.


I tried decreasing the glossiness.


I tried connecting IOR to Mix via ColorRamp node (I’m not sure if this is what you meant, I don’t know very much about how to use the ColorRamp node.)

I sort of see what you are saying about bump and normal map struggling with each other.

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There is how to test IOR - try changing divider positions and grays. http://www.pasteall.org/blend/25324
If bump and normalmap fight each other either stay with one or try invert bump - color invert node on output could roughly do.

Thanks for the suggestion! I tried one out, I don’t really know if I’m using it correctly. It definitely makes the color of the texture and the lighting more interesting! I would also need some direct lighting along with the environment map, right?
.


I downloaded the test you linked to, how do I use it?

I added the color invert node as you suggested.


Yeah, you definitely want some sort of traditional emission lighting scheme in play. And to be honest, enviromental lighting is more important in scenes with really glossy materials, like metal. Now in this case your hdri image is black and blue, so it stands to reason that the statue will take on some of that. You can turn the strength down from to 1 to .2 or .3 and turn up your mesh lights. But looking nice! I have always been a bit hazy about who wins in a bump/normal fight.

Thanks for all of your suggestions!