OTOY Forums

Hi! In my UE4 viewport my normal maps work correctly, but if I try to render my scene with octane - my normal maps are flip. How can i fix it? UE4.23

Could you show me an example? Or share the model and material you are using?

When you import normal maps, especially from Substance files or Polligon the green channel is flipped. Go into the normal texture file and click flip green channel. Unreal will then display the correct same direction.

Add a flatten normal node and a float value to adjust.

ChrisHekman wrote:Could you show me an example? Or share the model and material you are using?

yes sure, i use megascans library, here are screenshots of my problem, will they do? https://sun9-41.userapi.com/c206624/v20 ... ffjkrU.jpg https://sun9-52.userapi.com/c200624/v20 ... vC817A.jpg

EvolverInteractive wrote:When you import normal maps, especially from Substance files or Polligon the green channel is flipped. Go into the normal texture file and click flip green channel. Unreal will then display the correct same direction.

Add a flatten normal node and a float value to adjust.

Yes, i know it, but in UE4 viewport my maps work good

I 100% has the same problem, with certain normals get unreal to flip it so, both are wrong then either add a float negative value or a minus one node

EvolverInteractive wrote:I 100% has the same problem, with certain normals get unreal to flip it so, both are wrong then either add a float negative value or a minus one node

Yes, inverting a green channel works really good, but some of my projects need both renders, realtime render for a comfortable work and ray trace render for a production quality, if I'll switch a green channel of all my textures every time when i need production quality - it'll take much time. If the invert channel button will be placed right in the octane render settings - I think it would make working on some architectural projects like mine much more comfortable:) In any case, the ability to work with octane render in the UE4 is very cool, thanks to the developers!

I found the Quixel material you are using. It is working as expected on my end.
Seeing as the material is upside-down, am I correct in that you are scaling the model with a negative scale?
Nagative scaling along 1 or 3 axis can cause incorrect normal shading in Octane. I have passed the bug along, and ill also check if there is something i can do.

ChrisHekman wrote:I found the Quixel material you are using.
Seeing as the material is upside-down, am I correct in that you are scaling the model with a negative scale?

No, I initially checked the directions of all the normals of my object, they are OK, upside down doors-this is my UV mapping error. In addition to this, I checked other materials like concrete or wood textures, they behave in a similar way

The solution has already been given, in that some DDC for the green channel.
1. Get both Unreal and Octane going the same direction (even wrong)
2. Add to the normal node, a float value and a flatten normal
3. Adjust value positive or negative for best results.