Render problem - materials, sun - (solved)

[Andrejee]

Hi.
Newbie here, basic.
https://prnt.sc/qgkfz2
You can see the picture.
Corona sun is the default, targeted, and the target is in the interior.
There is Corona glass material on the window. Glass clear.

I can provide you with any info. Why is this happening, why I m getting so much light on the transparent Corona fabric material (fabric curtain) I applied to the curtain?
Thanks :)

Update: this is with the portal and it doesn't look it would change.
https://prnt.sc/qgla3x

Update2: now there is + a plane as background that does not emit light.
https://prnt.sc/qglgqu
It's still the same problem
Why is that succes rate so low?

[PROH]

Hi. I think it's caused by your materials, but without more info, one can only guess..

Here's two things to check out:
1) The glass mtl should be set to "thin"
2) The curtain shouldn't have any refraction

Hope it helps. Otherwise please provide some more info about your setup.

[Andrejee]

Hi. I think it's caused by your materials, but without more info, one can only guess..

Here's two things to check out:
1) The glass mtl should be set to "thin"
2) The curtain shouldn't have any refraction

Hope it helps. Otherwise please provide some more info about your setup.

Thank you kindly. I will try it right now, but I've tried some of it already.
These are the 2 pics of the same new render (stats and tools included).
https://prnt.sc/qhbjti
https://prnt.sc/qhbjy6

Ignore the geometry, please, I have to work on it. You can see a very high success rate, but...
1) The scene is very dark.
2) The background picture is somehow not colorful as it should be, I've placed it on the plane in between the portal and Sun(targeted). Maybe just to place the portal behind the background plane?
3) You see the sofa on the right and the sliding doors, and those sun rays. It's ok, cause I have a window behind that wall.
4) However, everything is so messy. Around the curtain, you see that sun rays are causing very much a bad effect. And down on the yellow wall right on the picture, you can see messiness. How to make all that clear.

I have set already the glass to be thin.
I will now try to disable refraction from the materials. When I render the scene, I see that my materials refract (absorb) other materials of objects next to them. I've seen that something can be done, some tutorial on the official Corona webpage or on the 3ds max. Something like disabling the red floor from interfering its color wth other object's materials. I'll google for it. Basically I need to stop reflecting all materials in order for them not to interfere with other object's material colors? Or just googling this tutorial.

5) Do you think that the sun and the background match ok in terms of the position of the rays?

And I'll try now with disabling refraction of the material of the curtain. I generally want a much brighter image, but when I was setting higher exposure it didn't go well.
Except for the yellow wall and black ceiling, and blue wall all left on the picture (hardly seen), and windows, glass in them, and the curtain - all other is without materials. And there are white materials on those lines between the ceiling and the walls.

6) And about the walls, I don't want them to be so plastic smooth. I've used corona default materials, but just changed color.

I'll try again, and see what can be done. Thank you very much for your patience, but please if someone can check the scene and that low level of brightness, it would be nice.

[Andrejee]

Update4:
I ve tried what you said. I ve disabled refractions on both the glass and the curtain. Set it to thin.But nothing..
Than I rendered the curtain with the wall only, not with the windows. Same problem from the first post
Then I isolated the curtain, and this time it rendered it normally. So, the solution was in choosing the darker no opacity fabric as sun illuminated to strongly those part of the curtain visible to it. Or maybe I should have just play with the opacity.

But what bothers me is that sun make reflactions around the curtain on the waĺl as you can see. Itself,that s ok, but the render is very much bad. And that curtain is dark from the interior, but colorful from the exterior. How to fix that?

Sorry guys for long texts and many questions,but I m just newbie for the rendering. I solved the background image and the sun position,that s not that important as the low brightwness of the scene. I m doing interior and I d veey much like that to be realistically bright, not as dark as it is in the previous two photos.

Update:
I'm now on PC. I've changed color of the wall where is curtain to white, and it's much easier to render. However, I am definetely not pleased by the results in that previous post. Should I leave it rendering for 12 hours or just there is something in the parameters I could have done maybe? 

[romullus]

Hi,
First of all, it would be nice if you could upload pictures to the forum, so we don't have to go through the links. Now on to the issues:

• Your colours are very bright and saturated, naturally, they will show strong colour bleeding. I suggest to reduce saturation and maybe brightness too.
• The scene is underexposed. Increase global exposure by 1-2 stops.
  
• Unless you really need a bright sunlight through the window, i'd suggest to change lighting to some diffused, more pleasing to the eye lighting. Maybe try some HDRI. Direct sunlight almost never looks good.
  
• Make sure that you set-up your background correctly and that it not interferes with scene lighting. See this article on how to do this properly. https://coronarenderer.freshdesk.com/support/solutions/articles/5000515605-how-to-create-background-material-in-corona-
  
• Your rays/s are very low. Your pc might be not very capable of rendering, or maybe there is some fundamental issue with scene set-up. Would it be possible to upload the scene for inspection?

[Andrejee]

Hi! Thank you very much on answer. It's not problem, but it's just easier to me to prtsc online now because of something, but I'll keep that in mind.
This is the Corona Benchmark test, so you're right.

Corona 1.3 Benchmark Finished
BTR Scene 16 passes
Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz
 Real CPU Frequency [GHz]: 2
Render Time: 0:21:10, Rays/sec: 382,573

1. So, my PC is low. Scene is not the problem. I'll try to exclude the window glass from the render. Cause it won't change a thing.
2. I have project to finish. I have assigned only Corona materials from the library except for the 4 lights that are not visible in the scene at all.
3. With that being said, do you or anyone else have tips on how to get the best out of my render with that low configuration and with Corona?
Should I do something with materials/light setup, render setup or use integrated Arnold or any other render? Or should I maybe reinstall the previous versions of Corona if that would help.

I'm now basically not interested in some high-quality materials, but just into everything to be simple. I'll even use just the textures only with material texture loader, without bumps or any other maps if that would help. Just the render to be decent as much as it can be, cause I'm now aware of the specs required. I was earlier, too, but I just have to finish this project and then I will be going for a PC upgrade. No plans for doing any other projects on this PC.
Know this is outdated, I'll google for this forum more to see, but basically just interested in tips what to use and not to use to render looks just simple and best it can look as it can look with this configuration in Corona?

Best regards

Update: Here s the link of what the guy got with Vray in Max11 with same CPU .So it is possible. He created the scene 8 years ago.
http://www.cgarchitect.com/2011/01/zen-house
So I should just delete unecessary pollygons.He used proxies Vray, but I will use Corona s. He said thanks to Vray displacement, and I ve tried to use Corona displacement for creating rugs,but it is different somehow, I didn't get it nor did I find a right tutorial - simple to do so as in Vray.
And for the postproduction I can use Photoshop.
I m new to all that stuff, but if that will take mo to finish the project, I'll learn it.

[romullus]

As long as your scene fits into the RAM of your PC, it can be rendered with the same visual quality as with the most powerful machines out there. It's just low-end PC will take much longer to finish the job, but the picture will look the same. There's no need to compromise on render settings, strip down textures and so on.

[Andrejee]

Thanks. So I'll leave it rendering for as long as it can be to be nice. Except that I have a problem that the scene is crashing in Max 2020 suddenly out of novwhere, I did not change anything, I've tried to load it in 2017 Max and it is also crashing there. I'll try to resave it to 2014 Max once again. And happy holidays.

[romullus]

Happy New Year!

If 3ds max is crashing because of Corona, it would best to report the issue and provide crash minidump, so that support team could look into the issue and provide further assitance. Please refer to this article on how to properly report an issue. https://coronarenderer.freshdesk.com/support/solutions/articles/5000524006-how-to-report-issues-3ds-max#crashes1

[GeorgeK]

Update: Here s the link of what the guy got with Vray in Max11 with same CPU .So it is possible. He created the scene 8 years ago.
http://www.cgarchitect.com/2011/01/zen-house
So I should just delete unecessary pollygons.He used proxies Vray, but I will use Corona s. He said thanks to Vray displacement, and I ve tried to use Corona displacement for creating rugs,but it is different somehow, I didn't get it nor did I find a right tutorial - simple to do so as in Vray.
And for the postproduction I can use Photoshop.
I m new to all that stuff, but if that will take mo to finish the project, I'll learn it.

For the displacement differences, please provide some screenshot comparisons and make sure your unit setup is correctly set to proper scales.

[Andrejee]

@Romullus
Thanks, I've resolved it with the 3Ds Max community. The problem was in many imported layers with animations and various things that were killing the scene. I've just deleted the layers, grouped all needed objects under the default layer and it is working. So Corona wasn't the problem.

@GeorgeK
Thanks. I don't use Vray, I've just watched tutorials on how to create a rug with Vray and at that time it was much easier - maybe due to the tutorial was great. But, nevertheless, I don't need displacement now for creating rugs. I'll provide screenshots in the future if that will be a problem.

When it comes to the sun+portal+background, I've learned and resolved it. I just need somehow to brighten up the scene + to make it more colorful - vivid. I'll follow the instructions here I got.
Thanks once again.
Best regards.