PBR Materials

Use this forum for general user support and related questions.
Post Reply
User avatar
dobe
Posts: 22
Joined: Thu Feb 15, 2018 7:43 am
Contact:

PBR Materials

Post by dobe » Mon Mar 04, 2019 4:01 pm

Hi,

I'm trying to use poliigon textures right now. But it does not work.
What's wrong?

For example, the wood reflects too much!
The noise in the simple scene is also very strong although I use PhotonGI?
Is it possible to use Displacement(Map)?

Blendfile: https://drive.google.com/open?id=1afsnm ... BY4RuwJblU

Thanks for helping,

Image
Attachments
screenshot.jpg
Win7 - i7 4770k - GTX 1070ti - GTX 1070 - 32RAM

marcatore
Posts: 184
Joined: Wed Jan 10, 2018 8:04 am

Re: PBR Materials

Post by marcatore » Mon Mar 04, 2019 4:24 pm

Could you post also the material references ?

User avatar
dobe
Posts: 22
Joined: Thu Feb 15, 2018 7:43 am
Contact:

Re: PBR Materials

Post by dobe » Mon Mar 04, 2019 4:27 pm

Wood: https://sketchfab.com/3d-models/wood-pl ... 74f31b8d7e
Concrete: https://sketchfab.com/3d-models/concret ... 903f515e49

I still have a Reflectionmap for each material. Is that needed for a good result?
octane and cycles do not need these textures!
Win7 - i7 4770k - GTX 1070ti - GTX 1070 - 32RAM

User avatar
B.Y.O.B.
Developer
Posts: 2243
Joined: Mon Dec 04, 2017 10:08 pm
Location: Germany
Contact:

Re: PBR Materials

Post by B.Y.O.B. » Mon Mar 04, 2019 5:24 pm

One thing I found so far is that the normalmaps are set up wrong:

wrong.PNG

This is how it's done correctly (enable the "Normalmap" checkbox):

correct.PNG
Support LuxCoreRender project with salts and bounties

User avatar
B.Y.O.B.
Developer
Posts: 2243
Joined: Mon Dec 04, 2017 10:08 pm
Location: Germany
Contact:

Re: PBR Materials

Post by B.Y.O.B. » Mon Mar 04, 2019 5:41 pm

Next, why the cache is not helping:

Your roughness textures should have gamma 1.0 instead of gamma 2.2 set, because they are non-color data. I will try to make this easier in the future, I logged it as a github issue.

With gamma 2.2, this is how the cache debug view looks like.
Blue means that the cache is used for this pixel, red means that LuxCore falls back to brute force path tracing.
Basically, your roughness textures are too dark because of wrong gamma, and they make the material too glossy to be safely included in the cache.

debug_1.jpg

After I fixed the gamma values of all roughness textures, this is the debug view:

debug_2.jpg

And indeed, the cache is now helping.
Before, it took 60 seconds to render 200 samples. Now it takes 42 seconds for 200 samples, and the samples are of much higher quality so the image is almost noise-free.

fixed.jpg

Here is the fixed scene: https://drive.google.com/open?id=18cxO1 ... XZEuIG1UOH
Support LuxCoreRender project with salts and bounties

tayo6
Posts: 36
Joined: Tue Jan 29, 2019 1:13 pm

Re: PBR Materials

Post by tayo6 » Tue Mar 05, 2019 8:18 am

B.Y.O.B. wrote:
Mon Mar 04, 2019 5:41 pm
Next, why the cache is not helping:

Your roughness textures should have gamma 1.0 instead of gamma 2.2 set, because they are non-color data. I will try to make this easier in the future, I logged it as a github issue.

With gamma 2.2, this is how the cache debug view looks like.
Blue means that the cache is used for this pixel, red means that LuxCore falls back to brute force path tracing.
Basically, your roughness textures are too dark because of wrong gamma, and they make the material too glossy to be safely included in the cache.


debug_1.jpg


After I fixed the gamma values of all roughness textures, this is the debug view:


debug_2.jpg


And indeed, the cache is now helping.
Before, it took 60 seconds to render 200 samples. Now it takes 42 seconds for 200 samples, and the samples are of much higher quality so the image is almost noise-free.


fixed.jpg


Here is the fixed scene: https://drive.google.com/open?id=18cxO1 ... XZEuIG1UOH
Probably a 2 pages pdf on pbr setup in luxcore would be good. Thanks for the explanation of the relationship between roughness texture and gamma

tayo6
Posts: 36
Joined: Tue Jan 29, 2019 1:13 pm

Re: PBR Materials

Post by tayo6 » Tue Mar 05, 2019 8:26 am

dobe wrote:
Mon Mar 04, 2019 4:27 pm
Wood: https://sketchfab.com/3d-models/wood-pl ... 74f31b8d7e
Concrete: https://sketchfab.com/3d-models/concret ... 903f515e49

I still have a Reflectionmap for each material. Is that needed for a good result?
octane and cycles do not need these textures!
I believe cycles doesn't really need reflection maps, yet it provides you with roughness node. Sometimes I connect textures of various types into the roughness node so I could get a unique reflection. Every material has reflection; it's either much or less

User avatar
dobe
Posts: 22
Joined: Thu Feb 15, 2018 7:43 am
Contact:

Re: PBR Materials

Post by dobe » Tue Mar 05, 2019 1:46 pm

thx for help ;)
Win7 - i7 4770k - GTX 1070ti - GTX 1070 - 32RAM

User avatar
Sharlybg
Donor
Posts: 1135
Joined: Mon Dec 04, 2017 10:11 pm
Location: Ivory Coast

Re: PBR Materials

Post by Sharlybg » Tue Mar 05, 2019 1:50 pm

the floor look almost diffuse and it isn't automatically cacheable. it is a large surface that can give more performance if cacheable.
Support LuxCoreRender project with salts and bounties

Portfolio : https://www.behance.net/DRAVIA

Post Reply