Chaos Corona Forum

General Category => Gallery => Topic started by: Dom74 on 2012-11-06, 02:58:13

Title: Corona watches
Post by: Dom74 on 2012-11-06, 02:58:13
My second render, with the same model, but some materials and lights adjustments.
( aluminium look better now ;).
I really appreciate Corona more and more.
Title: Re: Corona watches
Post by: Ludvik Koutny on 2012-11-06, 07:57:09
If you want to have contrasty and deep metal materials, then always be sure to use very low diffuse (gray RGB 4-12) Also, never use reflection level at 1, maybe except mirrors, but raise Fresnel IOR instead ;)
Title: Re: Corona watches
Post by: Dom74 on 2012-11-06, 13:53:54
Thanks, that's right, I use IOR 20 for metal, seems to be OK, but I have some problems with glass material, I use solid geometry, but a lot of light is "catched" by the glass, so all geometry behind glass are dark.
I have tried two sided material on 1 face glass objet, but some stranges shadows appears in render.
Title: Re: Corona watches
Post by: maru on 2012-11-06, 14:09:12
In this case I think it's best to use very thin (not single faced) geometry with 1-sided glass material.

In my opinion: leather is too shiny and too bumpy and metal is too smooth and too reflective.
Title: Re: Corona watches
Post by: Ondra on 2012-11-06, 14:26:10
Thanks, that's right, I use IOR 20 for metal, seems to be OK, but I have some problems with glass material, I use solid geometry, but a lot of light is "catched" by the glass, so all geometry behind glass are dark.
I have tried two sided material on 1 face glass objet, but some stranges shadows appears in render.
try 1-sided geometry with thin (twosided) glass. If there are any artifacts, post them here, maybe it's a bug.

When using solid glass, you get SDS configuration (specular diffuse specular). If you combine that with small light sources/HDRI with bright spots, you cannot render that correctly with any commonly used algorithm. There is however progressive photon mapping in daily versions of corona, which could work
Title: Re: Corona watches
Post by: Dom74 on 2012-11-06, 15:29:15
Thanks, I will try some tests with geometry/material
Title: Re: Corona watches
Post by: Dom74 on 2012-11-07, 01:32:24
I have made some tests, it seems that the glass twosided thin material cause shading artefacts.
The more I raise the reflection level, the more they are visible.
I have attached an image of renders.
Title: Re: Corona watches
Post by: Ondra on 2012-11-07, 11:53:13
Hm, can you post (simplified) scene? (just glass, frame, the object behind it with artifacts, and the light sources? Either here, or on my mail (keymaster at keymaster.cz)
Title: Re: Corona watches
Post by: Dom74 on 2012-11-08, 00:53:43
Hi.
I sent you the simplified scene to your email,
just render from camera009.
The problem is coming from sunlight I think, because, when I turn it off, or lower the intensity to 0.1 / 0.15, artefacts are not visible.
I can get rid off artefacts with sun intensity to 0.15 and glass reflection level to 0.4 up to 0.6.
thanks for your help.
Title: Re: Corona watches
Post by: Dom74 on 2012-11-10, 14:52:27
In this case I think it's best to use very thin (not single faced) geometry with 1-sided glass material.

In my opinion: leather is too shiny and too bumpy and metal is too smooth and too reflective.

You're right, I will change that (for leather),  but for metal, what do you mean ?
Title: Re: Corona watches
Post by: maru on 2012-11-10, 17:20:30
In this case I think it's best to use very thin (not single faced) geometry with 1-sided glass material.

In my opinion: leather is too shiny and too bumpy and metal is too smooth and too reflective.

You're right, I will change that (for leather),  but for metal, what do you mean ?
For me, it looks like cheap chinese aluminium. Too smooth and too bright. I would try to make it a bit rough and give it really low glossiness. But I may be wrong!
Title: Re: Corona watches
Post by: Dom74 on 2012-11-10, 18:17:42
In this case I think it's best to use very thin (not single faced) geometry with 1-sided glass material.

In my opinion: leather is too shiny and too bumpy and metal is too smooth and too reflective.

You're right, I will change that (for leather),  but for metal, what do you mean ?
For me, it looks like cheap chinese aluminium. Too smooth and too bright. I would try to make it a bit rough and give it really low glossiness. But I may be wrong!

I think you have good looking, I will try to follow you, thank for your advice.