Daz to Unreal exports hair with material problems

onyxlee_9b3cce7f35

Hey guys, I am playing with Daz to Unreal just now. I got this strange issue with the character's hair.

iRay render, notice also the clothes materials look significantly different:

The hair material looks like this, with opacity strength map slot being empty.

If I manually assign the hair transparency/opacity/alpha map to the material, it turns almost completely transparent. Do you think if this is a material problem or texture problem? Or the asset has some info that didn't get transferred into Unreal?

Thank you so much.

Hair T maps, only 2 available in the texture folder. I tried both, both look weird.

    

David Vodhanel

It looks like an extreme version of this problem.  http://davidvodhanel.com/daz-to-unreal-adjusting-hair-transparency/

I'd start by adjusting the transparency offset until it looks good.  Also, I'm not sure what happened to the scalp portion of the hair.  It's usually a masked material instead I think.  Did you change that?

onyxlee_9b3cce7f35

Thank you for your great work, sir.

I followed your instruction and found out that in this particular case, it feels like the top of the opacity is quite strange. The hair tip end looks alright. ( I color-coded to help to locate the poly group.) The scalp cap still looks weird when all the maps seem to be correct. I guess there's still something wrong with the opacity.

So you mean the hair issue is caused by each daz content vendor's different ways of managing their content?

Thank you again for your great work and great help!

David Vodhanel

I try to map the shader setup in Daz Studio to a material in Unreal.  It's also long render time vs realtime so I have to make some compromises.  The transparency in particular doesn't map across well always.  It's not that the content creator did anything wrong, I just didn't manage to make all the cases work. 

Those different parts of the hair are probably different materials.  Did you adjust the transparency on all of them?

onyxlee_9b3cce7f35

Hi David, thank you again for following up with me. I just found out the problem. It turns out that the cutout opacity and opacity strength, two very similar but confusing things that are interfering with each other. As long as I only keep one and disable the other one, it's much better. I still don't quite understand the difference between them, but in Daz, it's always cutout map that's controlling the actual opacity. There is no opacity strength map in Daz studio. But in Unreal, why do we have both cutout and opacity strength, and we need to use the transparency offset on top of them? (the cap still looks funky, but much better than before.)

From my WIP here, could you please give me some tips on how to make make the Unreal look a little more like iray render? The cap still looks weird. Also, the eyelash meshes are casting some solid shadows, completely ignoring the opacity map for the eyelashes. Is it possible to fix that?

David Vodhanel

I think that's probably kind of a bug from years before I even released the plugin.  I was trying to make a material that handled all options.  I later realized there were different shaders and I should have more materials that map to each of those. So I think which of those is used depends on the shader the hair is using.  I would recommend using the iRay shaders (MDL) since that's what I used the most.  They probably map better.

Also, if you prefer to make your own materials, there's a whole system for mapping the properties from Daz Studio to Unreal to simplify that process.  http://davidvodhanel.com/working-with-materials-in-daz-to-unreal/