Chaos Corona Forum

General Category => Gallery => Work in Progress/Tests => Topic started by: pionier on 2012-11-15, 11:21:32

Title: Not quite finished stuff... ;)
Post by: pionier on 2012-11-15, 11:21:32
hello,

I'm also testing Corona renderer, at first I will try to make a glass, this is how it's look like for now:

(http://img585.imageshack.us/img585/9081/szklankav05low.jpg)

(http://img20.imageshack.us/img20/6813/szklankav06low.jpg)

later I will try to add beer inside and maybe few drops on glass.

btw, nice to meet you :)

thanks,
peter
Title: Re: Not quite finished stuff... ;)
Post by: Ludvik Koutny on 2012-11-15, 11:24:40
Back side of the glass top looks oddly blurred, if you tried to retouch noise, i suggest to use noise reduction in Photoshop rather than smudge and blur tools :)
Title: Re: Not quite finished stuff... ;)
Post by: white on 2012-11-15, 11:31:57
"beer" sounds damn goood!!! :)....cheers
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-15, 11:34:20
Back side of the glass top looks oddly blurred, if you tried to retouch noise, i suggest to use noise reduction in Photoshop rather than smudge and blur tools :)

yes I know, DOF should be a bit smaller, I didn't use any smudge/blur tools as well as any 'retouch' trick so far, but thanks for your post :)

@white, thanks :)
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-16, 11:05:36
hello again,

I have a question, after reading the forum I'm a bit confused - in this scene when I had just glass, I used onsided (solid) mode and it's look ok for me, but what If I want add beer, should it be onsided or twosided mode?

at the moment I have the best result with glass on onesided and beer twosided mode, question is this a correct way of doing this?
Title: Re: Not quite finished stuff... ;)
Post by: Ludvik Koutny on 2012-11-16, 11:20:29
hello again,

I have a question, after reading the forum I'm a bit confused - in this scene when I had just glass, I used onsided (solid) mode and it's look ok for me, but what If I want add beer, should it be onsided or twosided mode?

at the moment I have the best result with glass on onesided and beer twosided mode, question is this a correct way of doing this?

Onesided... twosided means no refraction, like very thin glass, for example glass in windows or light bulb glass.

For beer, use same approach as you would in other renderer. Make a mesh of duplicating the  the inner side of the glass that will be a beer liquid, cap the top, invert normals and make it slightly larger so it intersects with the inner side of the glass a little bit :)
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-16, 13:04:25
hello again,

I have a question, after reading the forum I'm a bit confused - in this scene when I had just glass, I used onsided (solid) mode and it's look ok for me, but what If I want add beer, should it be onsided or twosided mode?

at the moment I have the best result with glass on onesided and beer twosided mode, question is this a correct way of doing this?

Onesided... twosided means no refraction, like very thin glass, for example glass in windows or light bulb glass.

For beer, use same approach as you would in other renderer. Make a mesh of duplicating the  the inner side of the glass that will be a beer liquid, cap the top, invert normals and make it slightly larger so it intersects with the inner side of the glass a little bit :)

do i get it right?
Title: Re: Not quite finished stuff... ;)
Post by: Ludvik Koutny on 2012-11-16, 13:51:45
hello again,

I have a question, after reading the forum I'm a bit confused - in this scene when I had just glass, I used onsided (solid) mode and it's look ok for me, but what If I want add beer, should it be onsided or twosided mode?

at the moment I have the best result with glass on onesided and beer twosided mode, question is this a correct way of doing this?

Onesided... twosided means no refraction, like very thin glass, for example glass in windows or light bulb glass.

For beer, use same approach as you would in other renderer. Make a mesh of duplicating the  the inner side of the glass that will be a beer liquid, cap the top, invert normals and make it slightly larger so it intersects with the inner side of the glass a little bit :)

do i get it right?

Yes, correct :)
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-16, 14:11:07
thanks Rawalanche, interesting approach with this intersects :)

it's getting better I think :P
Title: Re: Not quite finished stuff... ;)
Post by: maru on 2012-11-16, 17:11:31
I always thought it should look like this:
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-16, 17:24:58
me too ;)

your second image is interesting, I will have to try to do it with different ior value on each side of glass & beer.
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-16, 17:55:21
actually, the best way in corona would be to detach some glass faces and make the liquid from them, i.e. to have only single surface between the glass and water. But I have not tested if it works correctly
Title: Re: Not quite finished stuff... ;)
Post by: maru on 2012-11-16, 18:12:10
actually, the best way in corona would be to detach some glass faces and make the liquid from them, i.e. to have only single surface between the glass and water. But I have not tested if it works correctly

Yes, this is the method I posted. You create 2 separate objects that share one loop of edges (red spots). I think this is the most physically correct way. Creating a liquid volume which is a tiny bit smaller that the inside of glass gives very unnatural look. There are lots of tutorials on this. And best way to study this is by observing real life glasses. :) How about a non-corona tutorials section?
Title: Re: Not quite finished stuff... ;)
Post by: Chakib on 2012-11-18, 19:51:58
Method showed by MAru is the best way for liquid inside glass, can't wait to see the final result
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-23, 17:05:22
hello,

I did a test of something smaller:
(http://img832.imageshack.us/img832/9875/szklankav01.jpg)

btw, I find some nice topic about glass on maxwell render forum: http://www.maxwellrender.com/forum/viewtopic.php?f=15&t=17147
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 10:47:36
right, I think that making glass with liquid inside without having sss shader is a bit to hard, at least for me :P
here is the last test from it and I move on to something different :)

(http://img850.imageshack.us/img850/5961/szklankav02.jpg)

thanks,
peter
Title: Re: Not quite finished stuff... ;)
Post by: Ludvik Koutny on 2012-11-26, 12:45:45
right, I think that making glass with liquid inside without having sss shader is a bit to hard, at least for me :P
here is the last test from it and I move on to something different :)

(http://img850.imageshack.us/img850/5961/szklankav02.jpg)

thanks,
peter

Refraction falloff + low refraction glossiness ;)
Title: Re: Not quite finished stuff... ;)
Post by: Samurai Pizza Cat on 2012-11-26, 14:49:43
How come the glass is colored green in some areas ? I have the same issue with colored glass material.
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 16:40:04
Refraction falloff + low refraction glossiness ;)

I try this way:
(http://img827.imageshack.us/img827/6002/szklankav07.jpg)

kind of like this one :P
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 16:43:25
How come the glass is colored green in some areas ? I have the same issue with colored glass material.

that's what happened when you are not sure what to do ;)
Title: Re: Not quite finished stuff... ;)
Post by: Samurai Pizza Cat on 2012-11-26, 16:59:16
The new one looks good so far, few ice cubes and it looks delicious ! :)
 
Any suggestion on how to solve the colored glass issue ?
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-26, 17:08:16
Do you have exit color set to black? if so, what other components do you have on the orange-tinted material? If there is some reflection, make it orange too
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 17:19:34
The new one looks good so far, few ice cubes and it looks delicious ! :)
 
Any suggestion on how to solve the colored glass issue ?

thanks!

as for the question, I think that happened when you pick up wrong color for refraction?

btw, have a question as well: is corona more like maxwell renderer (I mean physically accurate) or like vray?
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 17:22:59
Do you have exit color set to black? if so, what other components do you have on the orange-tinted material? If there is some reflection, make it orange too

so when you are try to make colored liquid you should tint refraction, reflection and absorbtion colors?
and what if you want get juice, should I also use translucency?
Title: Re: Not quite finished stuff... ;)
Post by: Samurai Pizza Cat on 2012-11-26, 17:34:14
http://2.imimg.com/data2/QP/TU/MY-/gh-250x250.jpg

I´m trying to get this type of material, but changing the refaction color always results in a blueish tone (when using orange as color). Using orange as reflection color results in orange reflections as suspected.

Maybe a bug...



Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-26, 17:34:50
btw, have a question as well: is corona more like maxwell renderer (I mean physically accurate) or like vray?
Corona tries to get the best of both worlds. In terms of accuracy, it is definitely closer to the maxwell quality (see http://forum.corona-renderer.com/index.php/topic,255.0.html ;))

so when you are try to make colored liquid you should tint refraction, reflection and absorbtion colors?
and what if you want get juice, should I also use translucency?
Do whatever looks good ;). Since there is no participating media/SSS, you will be faking the material anyways ;)
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-26, 17:39:42
http://2.imimg.com/data2/QP/TU/MY-/gh-250x250.jpg

I´m trying to get this type of material, but changing the refaction color always results in a blueish tone (when using orange as color). Using orange as reflection color results in orange reflections as suspected.

Maybe a bug...

This is an energy conservation issue. Refraction gets what remains after reflection. If your reflection is pure red, you cannot then have any red in refraction, hence you get the complementary color.

I can think of 3 ways to do this:
1) what is currently implemented (strongly colored 1 component results in complementary color in the other
2) darkening of all color channels equally (then you would get no complementary color, but gray/dark).
3) breaking energy conservation (fake)

I dont know what is best. Vray lets you choose IMHO between 1 and 2

Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-26, 17:42:24
http://2.imimg.com/data2/QP/TU/MY-/gh-250x250.jpg

I´m trying to get this type of material, but changing the refaction color always results in a blueish tone (when using orange as color). Using orange as reflection color results in orange reflections as suspected.

Maybe a bug...

did you try with absorbtion color and distance or/and darken your refraction color?

btw, have a question as well: is corona more like maxwell renderer (I mean physically accurate) or like vray?
Corona tries to get the best of both worlds. In terms of accuracy, it is definitely closer to the maxwell quality (see http://forum.corona-renderer.com/index.php/topic,255.0.html ;))

so when you are try to make colored liquid you should tint refraction, reflection and absorbtion colors?
and what if you want get juice, should I also use translucency?
Do whatever looks good ;). Since there is no participating media/SSS, you will be faking the material anyways ;)

thanks for your answer,
I'm asking because I'm wonder if you can do staff like this guy here, watch youtube movie from: http://www.digitalartform.com/archives/2009/04/parabolic_ellip.html
having possibility to make it as in real world is realllly cool!

do you like my latest render? would be nice to get nice result and give you nice render for your gallery so any c&c are more that welcome :)
Title: Re: Not quite finished stuff... ;)
Post by: michaltimko on 2012-11-26, 19:41:35
Do u have diffuse set to 0, when using refraction ?
Title: Re: Not quite finished stuff... ;)
Post by: maru on 2012-11-26, 22:11:43
This is an energy conservation issue. Refraction gets what remains after reflection. If your reflection is pure red, you cannot then have any red in refraction, hence you get the complementary color.

I can think of 3 ways to do this:
1) what is currently implemented (strongly colored 1 component results in complementary color in the other
2) darkening of all color channels equally (then you would get no complementary color, but gray/dark).
3) breaking energy conservation (fake)

I dont know what is best. Vray lets you choose IMHO between 1 and 2
Why doesn't this happen in real life?
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-26, 22:47:57
This is an energy conservation issue. Refraction gets what remains after reflection. If your reflection is pure red, you cannot then have any red in refraction, hence you get the complementary color.

I can think of 3 ways to do this:
1) what is currently implemented (strongly colored 1 component results in complementary color in the other
2) darkening of all color channels equally (then you would get no complementary color, but gray/dark).
3) breaking energy conservation (fake)

I dont know what is best. Vray lets you choose IMHO between 1 and 2
Why doesn't this happen in real life?

In real life you have 2 basic types of materials: metals and other. Metals have only 1 mode of interaction: reflection. If the surface of a metal is rough, the reflection is blurred, but it is still a mirror reflection from very small randomly oriented faces. This reflection is always done in a single color. So no metal combines 2 colors in any way.

Other materials have 2 types of interaction: reflection and refraction + subsequent scattering (SSS, volumetric effects) inside the material. Reflection and refraction of almost all materials is white-only (again, no color combination). Once light is refracted, it can interact with the material (SSS, volumetric effects). Different wavelengths are absorbed differently, that means that the light that comes out is colored. There is no diffuse interaction, it is just fake to simulate materials with very subtle SSS (light enters the material, bounces in it a little, and goes out).

tl;dr: no material in real life scatters and refracts with different colors. Also, real materials also have MUCH lower albedo than what CG artists are using (~0.3).
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-27, 00:43:10
do you like my latest render? would be nice to get nice result and give you nice render for your gallery so any c&c are more that welcome :)
Yes, it looks great!
Title: Re: Not quite finished stuff... ;)
Post by: maru on 2012-11-27, 11:41:57
Ok, I think I get it. But what when (in real life) you have a glass object, covered in a semi-transparent coating. The glass is both reflective and refractive (coloured or not) and the coating is strongly coloured. So you end up with and object that is refractive, and has coloured reflection (filter). If the coating is RED, you only let inside light that is NOT RED. But you still don't see cyan coloured refractions inside, am I right?
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2012-11-27, 13:22:11
No, because those are in reality 2 separate materials. that interact differently. If the coating is metal, then you need it dilute its particles, because pure metal lets through no light. Then the illusion of transparency is created by mixing very small "everything goes through" and "nothing goes through" parts (think high-frequency noise in opacity map blurred by distance). If the coating is not metal, then the color is created by attenuating the light INSIDE the material. What comes out on one side is colored diffuse reflection, what comes on the other side is translucency and continues into the second material.

If you are interested in this, you can read more in
http://books.google.de/books/about/Digital_Modeling_of_Material_Appearance.html?id=FCJZO9DSeXAC&redir_esc=y
or in papers by Alex Wilkie:
http://cgg.mff.cuni.cz/~wilkie/Website/Home.html
Title: Re: Not quite finished stuff... ;)
Post by: maru on 2012-11-27, 15:15:34
Thanks! I really appreciate these links! Wish my shitty school would teach me stuff like this.
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2012-11-27, 17:56:55
Do you have exit color set to black?

yes I do :)

Do u have diffuse set to 0, when using refraction ?

yes I do :)

thanks for interesting chat here, I'm glad that few of you get inspired by me and make own glass renders!
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2013-10-06, 15:41:00
hello,

it's me again,

just want to share with you few renders I did for models presentation for making of Disney Vacation for chaos group,
I didn't want spend lot of time on it but I think it does the job well, at least I like this 'studio' setup and I love DOF from corona ;)

thanks,
P.
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2014-02-12, 00:33:48
back to testing corona, one more time glass topic ;P

Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2014-07-13, 16:46:17
fighting with caustic and render a bottle from my latest project, at the moment I try msi setup at 0 and bucket render ;)
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2014-07-13, 18:48:27
If you are not using blend material, this would be a great time to switch to VCM renderer...
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2014-07-14, 16:07:56
If you are not using blend material, this would be a great time to switch to VCM renderer...

I rendered this in ful hd frame over the night and was happy with the quality, as for vcm.. I did try it but get some bad result, lot of splotches ect even after 1,5h on half hd frame, photons was setup fo 30k But I am not an expert, maybe I setup it wrong somehow?

Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2014-07-14, 16:13:20
the photon radius needs to be tweaked based on scene... try decreasing it.
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2014-07-14, 16:35:51
Right, do I still need to put right number at msi when using vcm? Leave it as 25 or setup this at 0?
Title: Re: Not quite finished stuff... ;)
Post by: Ondra on 2014-07-14, 16:41:04
MSI is not working yet with VCM, so you dont need to change it, there is no effect
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2014-07-16, 17:36:32
hey,

well after many hours of testing vcm I give up and get back to PT, this is a new update, fixed lighting/reflection and compositing. still need a bit of love :D
Title: Re: Not quite finished stuff... ;)
Post by: pionier on 2015-08-28, 20:22:33
right, what do you think about this one? would you call it finished?
Title: Re: Not quite finished stuff... ;)
Post by: P&M on 2015-09-01, 00:21:48
Massive set of great renders Pionier.