Bump/Normal weirdness is making me sad
j cade
Posts: 2,310
So I'm not sure if this is a bug or just how Iray has always been and I've never noticed it before, but something is up with bump and normals... mainly they arent very... bumpy?
here's a shirt with tiling texture in cycles, no displacement, just bump and normals.
Here's that same shirt in Iray with as close to the same settings as I could get in Iray (same lighting even)
and there is a distinct lack of nice bumpiness, well clearly I just need to turn up the bump I think to myself so I do that and if I put it too high it gets... less bumpy somehow? what the what?
so I try a different texture one specidically designed for Iray sold at the store, and... well it looks bumpier than the cloth did
but then I stick it into blender and once again so much more bumpiness! I crave the bumpiness. Why won't you give me the bumpiness Iray
so please someone tell me that I've made some silly mistake and theres some easy fix for glorious bumpiness
edit for completeness sake the rubber texture with the normals turned up to 5
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Comments
this might be an obvious suggestion you already tried, but did you try switching between linear and srgb? I think DAZ imports all bump as sRGB even though other programs import as linear/non-color.
How do you actually do that in Daz? I tried fiddling with the gamma but switching it away from how it loaded made things even worse
yea i can't figure it out either LOL. I resorted to changing the gamma in an image editor. use 0.455 gamma or 2.2 gamma, depending on your image (or if one doesn't work try the other lol)
SubD Displacement Level? Makes a difference on a couple of shaders that actually use displacement. Can't find too many materials that use it though, they seem to rely on Bump and Normals.
Note: You can change individual image gamma with the Image Editor (faster) or Layered Image Editor (slow).
One thing I notice that your lighting looks muted in the 1st DAZ render you posted. Are you using spectral? I've noticed that spectral will mute lighting in some situations so I stopped using spectral.
Example: In this scene when I used spectral those lamps would loose their brightness. Spectral off & the brightness would return.
I think there is more diffuse/ambient light in the DS renders than in Blender's - look at the detail in the shadow under the arm, in the DS renders you can see a lot and it has a soft edge but in Blender it's pretty solidly dark with a much sharper cut-off. Diffuse light kills relief, hence the idea that candle and gas light are more flattering than electric.
First one looks good tbh; looks like cloth should look.
Here's the contrast turned up in Iray
and down in cycles.
To me cycles still looks more accuarate particularly the folds under the chest and the under arm shadow The light gets broken up in a much more natual looking way in cycles
I definitely have to agree with you, j cade. The normals don't look right in iray. Was this an iray material?
I did some digging, and it seems there's a bit of weirdness with normals / iray:
https://www.daz3d.com/forums/discussion/169221/iray-simple-comparison-bump-normal-displacement
I wonder what would happen if you clicked the "Invert Normals" button?
The Blender renders look so much better. Is this a problem with Iray?
Based on the fact that OP tested two different shaders, you would think that it wouldnt be problem with the normal map directions because the chance that the normal maps in both shader setups would be inverted seems low?
Yeah I've tried quite a few bump and normal maps, trying every setting I could possibly think of, and at this point it looks like it might just be an Iray thing, which is definitely buming me out a tad
What shader were you using for the "rubber" look of the shirt?
When I play with normals for bricks, they seem like they have a good deal of depth...
Yeah, naturally immediately after posting I found a normal set that actually looked like it had some depth (one of mech4d) so I'm upgrading bump and normals from completely borked to buggy/fiddly (the fact that some look okay doesn't really alter the fact that a buch of others dont despite working fine in other software)
upside is after examining her normal maps I got mine to actually work okay. downside that method involved partially bluring it so having actual depth + looking good in the details is still a bit of a wip
heres my improvement to my normal maps
much better but still some weirdness
+ a comparison of a very fashionable brick turtleneck
wow these normal maps actually look okay yay Iray!
(but still better in blender)
rubber material was Irender materials which are pretty great and I kind of want to try a bunch if them in blender now
aaaand the bricks with the normal maps turned up, since they were in cycles
it certainly adds in some detail, but notice how whole bricks get darker? still some funkyness
(that being said this texture would def get it done for me)
Very interesting! I wonder if Cycles just naturally has the normals set to the Iray equivalent of 2?
hah, pretty cool
j cade, how did you edit them to make normal maps look okay? Many look really bad in Iray I'm now noticing.
Forgot to respond to this
partially blurred them and mixed the blurred version back in with the clean one.
worth noting: I did this all in substance designer. I am not sure how well this would work elsewhere, as in substance it blurs across the edges of the textures correctly. If you did it in something like photoshop it would take mure effort to keep it from effing up the tiling
Interesting. I wonder why blurriness would increase the apparent height?