Need explanation how to remove small square patterns on the surface

Urban · February 25, 2019, 12:52:25 PM

Hi See attached pics/files. Unfortunately I cannot show you the zoomed out file.
Instead of me trying to errorsearch/test and rerender several times, it would be great if someone
could tell me what causes this hatched square pattern at the metal Surface?

An explanation about the file:
It´s shows an inzoomed pic of a metal surface.
the white colors are reflections from the surrounding HDRI.
There is a strange square pattern that shows up when rendering.
I thought it would dissapear efter hours of rendering time. But no it was still there when the render was at 100%. (3 hour later)

The scene tree of the metal polished surface as attachment
and data from material graph, color and bump.

My assumtions is that it has something with the scale that is so small now at the bump.
Well a lot of time can be saved if someone already know the answer.
Thanks in advance!
/Urban

DMerz III · February 25, 2019, 01:26:04 PM

How many samples are you using?
What render mode and settings are you using?

This just seems like it hasn't cooked long enough, try upping your sample rate and see if that clears things up.

Urban · February 25, 2019, 02:09:22 PM

Hi DMerz III !
Thanks for your quick answer.

the render settings shows 64 samples 8 cores and
It´s a huge file of 10000x7500pix To get high resolution (the exxect might be the opposite now or?).
Yes huge. And I don´t need so many pixels so this can be decreased. I have rendered this file the other day
with other settings and with 10000 pix too so as a matter of fact it must be something else involved..
But explains the long rendertime for you.

attached screenshot of render settings
I will try to upper sampling rate. Thx for the advice!

designgestalt · February 25, 2019, 03:32:56 PM

to me this looks like a pattern issue (but your sample is very small to make a valid comment)
could it be, that your texture map is not tileable ?
cheers
designgestalt

Urban · February 25, 2019, 03:44:58 PM

Hi designgestalt!
Thanks for the comment.
When is a texture map not tileable?

I have added a new file here in public
It shows the corner. The top surface has this strange unwanted facett effect

Cheers!
/Urban

Urban · February 25, 2019, 03:50:49 PM

DMerz III
Hi again!

I just tested to maximize the samples (256)
Unfortunately the strange facetts are still there

All the best
/Urban

TGS808 · February 25, 2019, 04:43:10 PM

Quote from: Urban on February 25, 2019, 03:44:58 PM
When is a texture map not tileable?

I think he meant seamlessly tile-able. So that you can't see where it repeats and starts over.

Urban · February 25, 2019, 04:49:18 PM

Hi TGS808!
Oki thanx for the explanation.So do you think that that is closer to the problem.
Am I using a texture that cannot be used?

I would like to mention in this case its better to get a natural
randomized silver-like surface feel instead of a machine made square one.

If not possible to get rid of it, It would be great if you could advice me to get away from this mathematical pattern
and randomize it.
Or is it a bug?
Have a great day,
/Urban

INNEO_MWo · February 25, 2019, 09:27:22 PM

Does the pattern still exist if you deactivate the diffuse label material?
It should be recognizable in real time render view port.

designgestalt · February 26, 2019, 12:55:05 AM

hey Urban,
I am sorry, I thought this was common language. When a Newbie appears, you never know, if he is new to the world of cgi or only new to KS...

yes, I was refering to a seamlessly tileable map.

but it also could be, that the map is very small and inhomogeniuos (i.e. has a bright spot) yet could still be tileable. it still would look strange on a larger model.
I have your "metal-texture" under suspicion, here, but again, its hard to say with the information we have.

the easiest way here would be, if you create a new file with only a cube in it (best case would be with your lighting set-up!), apply your material and spread a .ksp file here, for someone to take a look into.
I assume, this is a small issue and can be dealt with quickly !
the person helpin you will also tell you quickly what the problem was, I am pretty sure!
cheers
designgestalt

Urban · February 26, 2019, 05:06:52 AM

Hi again designgestalt!

No problem. I thought it was that you ment with "tiled", but I needed to question to be 100%.
I understand that the problem will be much easier for you to solve if i create a cube with the same material.
I will try to fix this during the day. If I cannot recreate the problem then it must be the cad-file (Rhino).

Thank you very much for the help so far
Files incoming..

All the Best
/Urban

Urban · February 26, 2019, 06:41:18 AM

Hi designgestalt Lets go!Here is a cube with a similar pattern
I imitated the data as much as I could.
The HDRI is another, but the effect occurs.
I think it has something to do with the dust wipes pattern?
Well I´m eager to hear your answer and solution.

FYI: The pattern is even more visable on the bottom side of the cube.
Have a great day,
Cheers
/Urban

Esben Oxholm · February 26, 2019, 07:03:39 AM

Hi Urban.
It is definitely the dust causing the problem.

By judging from the name of the texture, you have picked a very low res preview file (_flat) and scaled it super small.
If you select the dust texture and hit C on the keyboard you'll see the raw color output from the texture. See attached below.

The solution will be to use the file called dustsmall004_overlay... and use a larger scale. I've used 3 in the example shown below.
Hope it helps.

Cheers,

Urban · February 26, 2019, 07:39:35 AM

Hi Esben!

Thank you for the answer. It must be that. thank you!
Just a question. Instead I added the overlay file now. But It does not look identical with
your file. What settings am I missing? what is causing "the black line pattern"
Cheers,
/Urban

Esben Oxholm · February 26, 2019, 08:46:45 AM

Are you viewing the object from below?
Looks a bit like groundplane interfering.