Matching roughness between UE4 and SD/SP
polycounter lvl 11
Hello guys,
Posting this here as well, as the allegorithmic forum seems slightly slower than the PC community. I hope it doesn't bother anyone.
As I am new in both UE4 and the allegorithmic software, I am most likely missing something super obvious.
How do I sync the look on metallic surfaces between SP/SD and UE4?
If I have a metallic surface in unreal, and apply my textures to that mesh's material one by one, everything seems fine until I put in the roughness map. Then it doesn't look like what I see in SD/SP at all. And I cant seem to figure out wh. No matter how I multiply/overlay/whateverify the roughness map with in unreal.
Im sure it's something small and easy. Can someone help me figure it out?
Posting this here as well, as the allegorithmic forum seems slightly slower than the PC community. I hope it doesn't bother anyone.
As I am new in both UE4 and the allegorithmic software, I am most likely missing something super obvious.
How do I sync the look on metallic surfaces between SP/SD and UE4?
If I have a metallic surface in unreal, and apply my textures to that mesh's material one by one, everything seems fine until I put in the roughness map. Then it doesn't look like what I see in SD/SP at all. And I cant seem to figure out wh. No matter how I multiply/overlay/whateverify the roughness map with in unreal.
Im sure it's something small and easy. Can someone help me figure it out?
Replies
Since it's a greyscale image used to get precise values for roughness you don't want any gamma correction messing with the values/levels, so un-ticking sRGB should make the texture display correctly
Hope this helps out
Wasnt a one click solution, though. Maybe just lihgting, but will look more into it tommorow
Thanks a lot, Simmo!
I am also using Substance Designer and UE4, and while the look of the materials do seem on par between the two programs (especially after the UE4 sRGB uncheck mentioned above), I am a little suspicious of some of my settings, and want to make sure I am doing the right thing in regards to my export setup from Substance Designer (ver 4.5.1).
Should I be using the 'sRGB to linear' node as the last node between my graph and the roughness and metallic outputs? Is what I see in the viewer not displaying the true roughness without this node, or am I doubling (overly adjusting) the map by using it?
Also, an issue I had after saving my outputs as .tga from Substance, is that Unreal would not recognize these files and gave an error upon import. This was later fixed after changing the mode from Gray to RGB in Photoshop, however. So, should I export maps in another format, to save that step, or perhaps change another setting to correct this?
Thanks in advance for your help.
Hi,
You don't need to use a conversion node in the graph itself. If the inputs for the shader are images that are meant to be displayed, for example base color, then they are most likely in sRGB space so they need to be converted to linear space before computations are performed in linear space. In UE4, you need to set the Texture to sRGB to have it converted.
Some images are not meant to be displayed such as normal, height, roughness and metallic maps. Therefore, there is no need to encode them in sRGB. They are to be treaded as linear inputs and thus you leave the sRGB unchecked for the texture.
If you are using a substance (sbsar), the substance plugin will correctly set the color space for the generated maps.
So its best to not try and do the conversion to linear space in the substance graph as the Texture setting in UE4 will still make the conversion.
Cheers,
Wes
I realized later that what I was authoring in Substance Designer (not using the UE4 plugin by the way) for the roughness and metallic was linear already, and would not need the conversion node, as long as sRGB was unchecked inside the texture properties in UE4.
As far as the targa issue, I went ahead and setup a custom output node in Substance, and used an RGB merge node to forward the roughness to R, the metallic to G, and the ambient occlusion to B, and this is automatically saved out in RGB (not gray as before) that Unreal imports just fine. Doing that also allows me to skip that step in Photoshop and save some nodes in the UE4 material as well.
Thanks again, cheers!
Honestly it's crazy to expect to use Photoshop AFTER Substance Designer; you should only really need it before Designer, as an input. Anything you'd want to do afterwards, you can do in Designer as well, but in a non-destructive, smart way.
Yeah, it's kind of sad, but I haven't touched Photoshop since getting Designer and Painter
Could someone from Allegorithmic talk about this more? I still feel like even with sRGB checked off roughness, the rendering is different between Substance and Unreal. Is that just me, or is this real?
It's fine either way I'd just like to know.
The difference becomes more visible with high roughness on metallic materials.
However I'm interested in seing the difference you're mentioning, can you post a screenshot?
What should be set to SRGB?
All the rest = linear.
it's easy.
What am I doing wrong?
Hi,
You need to make sure that the metal and roughness maps have sRGB unchecked in the texture editor. They need to be interpreted as linear.
Cheers,
wes
I had them unchecked. Putting the object in another scene fixed it somehow.