Micro detail texture maps now come with Daz 8.1 characters and some PA/third-party characters, before now we've only been able to use them in less than ideal ways that have resulted in a loss of detail and quality.
There might be better ways to do this worked out in the future, as I've only spend the last day or so looking into this, although I've read an article on normal map blending methods, looked at the DS Iray MDL files and looked at several blender Eevee/Cycles shader setups.
For this I'm using Jacqueline 8.1's arm textures.
- The overall node setup.
For normal map blending we want to use the 'reoriented normal' blend mode, which is currently the best method, something that the blender render engines don't appear to have access to.
- Connect the base character normal map to a 'Composite Texture Layer' node leaving the blending settings at default and then connect that to Layer 1 on a 'Composite Texture' node with 2 inputs added. Like Photoshop this acts as our base layer that we then layer others on top of.
- Connect the micro details normal map to another 'Composite Texture Layer' node setting the blend mode to 'reoriented normal' as shown bellow and then connect it to Layer 2 on the 'Composite Texture' node. The 'Composite Texture' node can then be connected to normal pins in your material.
- The blend settings for normal maps.
- SkinMicroDetail04.png (6.63 KiB) Viewed 1460 times
For roughness maps there is no "best" blend mode, but multiply gives good results from my testing, try out some different ones and pick the one you like.
- Repeat the same node setup as used for normal maps, but select the multiply blend mode in the 'Composite Texture Layer' node connected to Layer 2.
- The blend settings for roughness maps.
- SkinMicroDetail03.png (6.26 KiB) Viewed 1460 times
Connected the weight or W map to the opacity pin of the 'Composite Texture Layer' nodes connected to Layer 2 for both the normal and roughness 'Composite Texture' nodes, this controls where and how strongly micro detail is applied.
Daz does not provide W/weight maps for the Body or Head surfaces (most other vendors don't provide any at all), so don't connect one in those cases.
Connect a 2D transform node to the both Micro Detail textures as we want their scale to match. You can get a scale to work from by looking in the matching surface under the Surfaces tab in Daz Studio. You'll generally see values between 30 and 50 with the face surfaces having a smaller scale than the rest of the body. To convert the Iray values to something you can use in Octane divide 1 by the Iray scale, so 1/45 = 0.025 as used in the example bellow.
- The 2D transform node for scaling down the micro detail maps.
- SkinMicroDetail02.png (9.42 KiB) Viewed 1460 times
The results, I've included the reflection and normal pass to help show the difference between having micro detail turned on or off:
- Jacqueline 8.1's arm with no micro detail.
- Jacqueline 8.1's arm with micro detail applied.
The results vary quite a lot depending on the lighting, camera angle, how close you are and the textures/character used. Daz 8.1 character actually have very detailed roughness and normal maps so the difference is minimal, however a lot of both new and old characters (Daz Gen 8 and older characters for example) have relativly flat normal maps that only have sculpting details and not skin texture, so you will see much more obvious results in those cases.
And don't forgot you can use any micro detail textures from any character on any other character (invert the roughness map if the character uses specular maps rather than roughness maps).
I hope this helps anyone looking for how to do this.
