Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: flood on 2018-09-12, 13:14:35

Title: object not smooth
Post by: flood on 2018-09-12, 13:14:35
I'm rendering a scene with a Tree and some apples (cartoon style).

Everything renders good but for some reason the Apples don't render smoothly.
I have checked the Polygon smoothing groups and every polygon has the same smoothing group.
I have also changed the material to a standard corona material. And still the same problem.

So I created a new object (sphere) and used the new standard corona material on it and the problem also happens with this sphere.


What is causing this problem? All the other objects in my scene renders fine.
Title: Re: object not smooth
Post by: romullus on 2018-09-12, 15:22:36
Does this material uses translucency or SSS? Could you show screenshot of that material?
Title: Re: object not smooth
Post by: Beanzvision on 2018-09-12, 15:41:30
Definitely looks like faceting. See if this helps:
https://coronarenderer.freshdesk.com/support/solutions/articles/12000012390-my-sss-objects-are-faceted-

Thanks,
Title: Re: object not smooth
Post by: maru on 2018-09-12, 16:38:43
Sending the problematic scene would be probably the easiest solution. ;)
Title: Re: object not smooth
Post by: flood on 2018-09-12, 16:45:08
I can reproduce the "problem".


1. Create a sphere (make it 60 cm)

2. Create light : standard > Target spot

change te light parameters to:
-General Parameters>Shadows>CoronaShadows (on)

-Corona Shadows> Use area (soft) shadows
-Change the area radius to 10000


3. Create corona Camera


4. Add CoronaMtl material to the sphere (leave it standard, give it a color, like red)

5. ...and render the cameraview


The problem is the high area radius of the are (soft) shadows.
But I need to go that high to create a non-realistic look.

If i turn off or lower the soft shadows the problem is gone.

Is this a bug or something "meant to be"?
Title: Re: object not smooth
Post by: Jpjapers on 2018-09-12, 16:54:12
I can reproduce the "problem".


1. Create a sphere (make it 60 cm)

2. Create light : standard > Target spot

change te light parameters to:
-General Parameters>Shadows>CoronaShadows (on)

-Corona Shadows> Use area (soft) shadows
-Change the area radius to 10000


3. Create corona Camera


4. Add CoronaMtl material to the sphere (leave it standard, give it a color, like red)

5. ...and render the cameraview


The problem is the high area radius of the are (soft) shadows.
But I need to go that high to create a non-realistic look.

If i turn off or lower the soft shadows the problem is gone.

Is this a bug or something "meant to be"?

Any reason youre not using a corona light?
Title: Re: object not smooth
Post by: flood on 2018-09-12, 17:00:47
Yes the main reason was this :
https://forum.corona-renderer.com/index.php?topic=19887.msg124055#msg124055

You can download the sphere test file (see attachment)


Title: Re: object not smooth
Post by: Jpjapers on 2018-09-12, 17:07:43
Yes the main reason was this :
https://forum.corona-renderer.com/index.php?topic=19887.msg124055#msg124055

You can download the sphere test file (see attachment)

Ah i see. I agree its likely the area shadow radius causing the issue
Title: Re: object not smooth
Post by: maru on 2018-09-14, 16:04:37
Easy to reproduce. Will report to the devs.
Title: Re: object not smooth
Post by: flood on 2018-09-14, 16:16:51
Easy to reproduce. Will report to the devs.

Thank you.

I have made the decision to totally delete all of my lighting setup and take a different approach. This has taking me two days of very very hard work.
I was a mentalray user and to get the results I wanted with Corona I wanted to try and use everything I learned from mentalray and use that knowledge to get the lighting setup I needed. After months of testing and tweaking I now understand that this was totally wrong.

This is my first real Corona project i'm working on and I'm still in the learning process.

Since yesterday I have successfully used Corona in a different way then I was used to and i'm getting better results without adding lights like crazy to get where I want to be.

The childrensbook project I'm working on is almost finished, i'm rendering the final images right now. It's has been long hours for the past few days but I'm finally going towards the end.
Title: Re: object not smooth
Post by: Jpjapers on 2018-09-14, 16:39:44
Easy to reproduce. Will report to the devs.

Thank you.

I have made the decision to totally delete all of my lighting setup and take a different approach. This has taking me two days of very very hard work.
I was a mentalray user and to get the results I wanted with Corona I wanted to try and use everything I learned from mentalray and use that knowledge to get the lighting setup I needed. After months of testing and tweaking I now understand that this was totally wrong.

This is my first real Corona project i'm working on and I'm still in the learning process.

Since yesterday I have successfully used Corona in a different way then I was used to and i'm getting better results without adding lights like crazy to get where I want to be.

The childrensbook project I'm working on is almost finished, i'm rendering the final images right now. It's has been long hours for the past few days but I'm finally going towards the end.

Yeah mental ray and corona are two very different beasts and there arent that many parallels to be drawn IMHO
Title: Re: object not smooth
Post by: maru on 2018-09-14, 17:31:48
In Corona usually the most straightforward solution works best. If you need a light, use a Corona light. :)
Title: Re: object not smooth
Post by: maru on 2018-09-21, 10:57:50
We will look into this, however it's definitely not high priority, as you need a very specific setup to trigger the error.
The current solution is to use Corona Lights whenever possible (they work fine with a similar setup).