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Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 2:44 pm
by tom.sb
Hi everyone !

Here is my problem : I need to apply various pattern designs on 3D glass models

Here's what I'm looking for : https://imgur.com/l2PlG6n

Here's the issue : https://imgur.com/XeO5OwC

I use UVW Mapping on my pattern's material with "Simple projection" and side to "Both" with the "Tile" option.
On some models, the pattern get distorted, much bigger on the parts that are rounded, not plane (maybe this is the reason?)
There's also some dots that shouldn't be here. You can see the original pattern : https://imgur.com/iuYWnzi
Thanks in advance ❤️

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 3:01 pm
by masterzone
Hi Tom, welcome aboard. The problem is the projection, if you are using UVW mapping you need the unwrapped UV otherwise distortions occurs. If you are not into the UVW argument you must change your projection on something else like Cylindrical mapping to avoid distortion. Let me know :)

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 3:07 pm
by tom.sb
masterzone wrote: Wed Jun 03, 2020 3:01 pm Hi Tom, welcome aboard. The problem is the projection, if you are using UVW mapping you need the unwrapped UV otherwise distortions occurs. If you are not into the UVW argument you must change your projection on something else like Cylindrical mapping to avoid distortion. Let me know :)
Hi masterzone ! Thanks for your quick answer.

What do you mean by unwrapped UV? I tried changing the projection to cylindrical, sphere and all the others but the only one that gives a realistic result is UVW mapping, the others are distorting the pattern a lot. Frontal is the only one that keep my pattern normal but of course it isn't realistic since the pattern isn't following the object.

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 3:13 pm
by tom.sb
Here you can see the glass model without and with the pattern added : https://imgur.com/a/nm3GZv8

I don't understand why the middle zone is working while the rest is taking the orange or dark grey color from the pattern with huge distortions.

I found this video : https://www.youtube.com/watch?v=Xe-HZQU5I8c do you think that doing the same to my glass renders would solve the problem? Thanks !

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 4:34 pm
by masterzone
Hi Tom, I think this issue is definitely bad UVWs so you need to unwrap them...
As said before , what about Cylindrical mapping? if you apply on it with Cylindrical projection you can right click into it and choose "adapt to object" for a good placing and after you can use tag percentages for change the size :)
Give me some minutes for making a video...

ps: if you click into "full editor and preview" forum button below you can drag and drop image from your desktop into the message body instead to use imgur :)

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 4:52 pm
by tom.sb
Alright so Cylindrical using "fit to object" does work pretty well.

But I have to do something like 30% lenght U and 100% lenght V to get a normal look.
Otherwise it's working pretty well at the moment !!

Thank you so much, I'll try if I have a better result using unwraped UV, I saw that Substance Painter can automaticaly generate uv maps from 3D models ?

Sincerely,
Tom

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 4:53 pm
by masterzone
ok here is the video: https://youtu.be/FJQDvrIobQg

Re: Need help : Adding a pattern on a glass model

Posted: Wed Jun 03, 2020 4:56 pm
by masterzone
Yes if you work with substance the bridge can unwrap for you the object but there are many kind of unwrapping way, you need a very good unwrapping to make a label fit on it perfectly. There are also some way for unwrapping objects that give you the possibility to paint into the object without some special actions but is not suitable for labels or something else...
Anyway you can try to substance as well for the unwrapping...Remember that Cinema4D S22 is now shipping with a new unwrapping tools :)

Re: Need help : Adding a pattern on a glass model

Posted: Thu Jun 04, 2020 9:43 am
by tom.sb
masterzone wrote: Wed Jun 03, 2020 4:56 pm Yes if you work with substance the bridge can unwrap for you the object but there are many kind of unwrapping way, you need a very good unwrapping to make a label fit on it perfectly. There are also some way for unwrapping objects that give you the possibility to paint into the object without some special actions but is not suitable for labels or something else...
Anyway you can try to substance as well for the unwrapping...Remember that Cinema4D S22 is now shipping with a new unwrapping tools :)
Hi masterzone !

Thank you so much for your time, it works fine using cylindrical and fit to object ! But I still have an issue with some black dots appearing on the render. I never saw such a thing, maybe due to the glass transparency or something like that ?

Re: Need help : Adding a pattern on a glass model

Posted: Thu Jun 04, 2020 10:27 am
by tom.sb
Sorry I'm quite a noob, didn't played with C4D for a long time..

My pattern gets black on the back of the glass. I just changed the glass material a bit but not sure this would make this black. Also switched my render settings to physical. But at least the dots are gone !