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Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: Alex Abarca on 2014-02-11, 06:09:54

Title: tree Translucency
Post by: Alex Abarca on 2014-02-11, 06:09:54
Anyone one have any ideas on how to make this look realistic. I used color correction in the translucency swatch I took the main bitmap and made orangey, then I instanced it in the refraction swatch.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-11, 06:12:21
Here is more info
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-11, 06:48:13
Here is the file and the scene

https://www.dropbox.com/s/6kvq9hvwld911e1/TreeTranslucency.zip
Title: Re: tree Translucency
Post by: Ludvik Koutny on 2014-02-11, 10:39:59
Mistakes you are doing:

1, Do not use refraction, use just translucency. Set refraction level to 0, and remove map from refraction slot. Only parameter you need to tweak is translucency fraction.

2, You use way too much saturated texture for leaves. It does not look like natural green, but like cartoon acid.

3, Use glossiness map instead of reflection map. And if you after all still decide to use reflection map too, then make sure reflection color texture is greyscale. Tree leaves are not metal material, so they do not tint their reflection.

Look here https://www.google.cz/search?q=tree+leaves&tbm=isch&tbo=u&source=univ&sa=X&ei=1u_5UonUA4rIhAfGxIHAAQ&ved=0CCsQsAQ&biw=1920&bih=1115 and you will notice tree laves are a lot less saturated
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-12, 20:30:19
I'll give it a try, thank you.
Title: Re: tree Translucency
Post by: astudio on 2014-02-14, 10:51:46
It's look like leaves veins are in wrong direction
Title: Re: tree Translucency
Post by: gracelorn on 2014-02-14, 12:40:23
Well spotted, astudio ;) Looks like the texture is flipped.
Title: Re: tree Translucency
Post by: romullus on 2014-02-14, 15:59:04
I tweaked your material a little bit. Obviously there's a room forimprovement even more, but for now it should do.
Scene is there: https://saugykla.teo.lt/Shares/Home.aspx?ShareID=9159e741-d8d5-4587-be4e-6fe6bf619ae6 (https://saugykla.teo.lt/Shares/Home.aspx?ShareID=9159e741-d8d5-4587-be4e-6fe6bf619ae6)
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-15, 01:35:31
Well spotted, astudio ;) Looks like the texture is flipped.

True, I didnt notice. I have to look closer!


I tweaked your material a little bit. Obviously there's a room forimprovement even more, but for now it should do.
Scene is there: https://saugykla.teo.lt/Shares/Home.aspx?ShareID=9159e741-d8d5-4587-be4e-6fe6bf619ae6 (https://saugykla.teo.lt/Shares/Home.aspx?ShareID=9159e741-d8d5-4587-be4e-6fe6bf619ae6)

That looks totally awsome Romullus! I am going to take a close look at your material slot.

Below are other tests that I been doing in regards to leaves and translucency. The bad thing is that I am testing with flat models (leaves), it would be nice to have concave leaves. But in these examples I managed to get just a tad of translucency and warmer colors where light seems to pass. Please feel free to crit. Oh and sorry for the bad renders, I have a slow machine, but I rendered regions in places that are of interest.
Title: Re: tree Translucency
Post by: maru on 2014-02-15, 10:30:21
I think leaves should have more "juicy" yellowish colour where the light is passing through. Some more reflectivity and a subtle bump map could also help. All these things are probably dependant on the kind of plant you are referring to. :) And yes, better geometry (for example leaves bending in some direction) would be nice.

Here are some examples:
(http://www.uprawyekologiczne.pl/Photos/leszczyna.jpg)

(http://sklep.szkolka.radom.pl/product/image/4897/klon-princeton-gold.JPG)



Title: Re: tree Translucency
Post by: vkiuru on 2014-02-16, 11:41:55
I think it's a mistake to tweak such materials in HDR lighting and/or taking closeup renders. Most of the time, at least in archviz, vegetation is going to be in the background and as such should look convincing when scattered across a wide area and should work with the most simple lighting.

Threads on this subject usually have a trend of showing off nice closeup shots of leaves lit with nice HDR lighting which IMO begs the question, are you actually tweaking a material or just showing off something that works in strictly controlled environment? Also it's extremely easy to get a material to look organic when you use an overcast lighting, but as soon as you introduce bright sunlight to the equation such materials oftentimes break down. My suggestion is to show how your material works in both overcast and sunlit conditions when doing these tests.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 01:34:16
I think leaves should have more "juicy" yellowish colour where the light is passing through. Some more reflectivity and a subtle bump map could also help. All these things are probably dependant on the kind of plant you are referring to. :) And yes, better geometry (for example leaves bending in some direction) would be nice.

Here are some examples:
(http://www.uprawyekologiczne.pl/Photos/leszczyna.jpg)

(http://sklep.szkolka.radom.pl/product/image/4897/klon-princeton-gold.JPG)

Is corona capable of doing this?
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 01:42:32
I think it's a mistake to tweak such materials in HDR lighting and/or taking closeup renders. Most of the time, at least in archviz, vegetation is going to be in the background and as such should look convincing when scattered across a wide area and should work with the most simple lighting.

Threads on this subject usually have a trend of showing off nice closeup shots of leaves lit with nice HDR lighting which IMO begs the question, are you actually tweaking a material or just showing off something that works in strictly controlled environment? Also it's extremely easy to get a material to look organic when you use an overcast lighting, but as soon as you introduce bright sunlight to the equation such materials oftentimes break down. My suggestion is to show how your material works in both overcast and sunlit conditions when doing these tests.

I agree with you, I think it also has alot to do with your HDRI exposure you decide to use. With some of them (that don't work) I do get out of whack colors. With the VIZpeople HDRI there is minimal differences in color varience. Color correction (map) is a key controller to have, because you can de-saturate as needed depending on the scene. But I totally agree with you, direct sun light is probably the best solution for making materials. The translucency will be the same in both scenarios, its just the color one has to watch out for. Here is a render from the tree without the HDRI.

Can anybody share their material composition for leaves/plants?...Thanks!
Title: Re: tree Translucency
Post by: Ondra on 2014-02-17, 08:12:58
Is corona capable of doing this?

Yes, see the gallery on homepage
Title: Re: tree Translucency
Post by: maru on 2014-02-17, 12:56:45
Ok, here's my try. Maybe the translucency is a bit too exaggerated and leaves could be more reflective but it's because I've been looking at it for too long. :)
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 18:31:46
Impressive Maru' thank you for showing, I have to try this. Can you show me your slate view?
Title: Re: tree Translucency
Post by: maru on 2014-02-17, 18:47:41
Here. And don't look at reflectivity map. It's probably close to useless. Good diffuse and translucency maps and values are the key here.
You can download the model with textures from here:
http://www.viz-people.com/free-stuff
Title: Re: tree Translucency
Post by: Ludvik Koutny on 2014-02-17, 19:21:16
I know this is completely unrelated, but why don't you instance that bitmap node instead of having it there 4 times? :D
Title: Re: tree Translucency
Post by: maru on 2014-02-17, 19:41:55
Hah, there is no real reason, that's because I was doing it very quickly and dirty. :)
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 19:48:49
Its look Awsome Maru, just like in the movies http://img2.tvtome.com/i/u/4590d3ec9f3442bbc2886089f36c2dc7.jpg

 I am going to try this can you show me your slate view, please.

Thanks!
Title: Re: tree Translucency
Post by: Ondra on 2014-02-17, 19:52:59
Hah, there is no real reason, that's because I was doing it very quickly and dirty. :)

You can save a LOT of time by instancing maps as much as possible in shadertrees and different slots of a single material.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 20:11:19
Hah, there is no real reason, that's because I was doing it very quickly and dirty. :)

You can save a LOT of time by instancing maps as much as possible in shadertrees and different slots of a single material.

That's Ok, I totally get it. The params are the magic.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 20:17:52
Here what I got so far. What do you guys think?

I'm going to go download the free trees and test maru's material worlflow now.

I am missing some parameters, guess I need the dailybuilds.
Title: Re: tree Translucency
Post by: romullus on 2014-02-17, 20:27:17
You're doing this mistake again. Tree leaves doesn't need refraction. By puting map in this slot, you hurting both, material believability and render time. Don't do this.

Edit: btw, if that map structure for translucency slot, you borrowed from my scene, you may want to replace it by something else. I did it in hurry and i don't think it's suitable in this situation. I feel guilty for this :]
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 20:38:31
You're doing this mistake again. Tree leaves doesn't need refraction. By puting map in this slot, you hurting both, material believability and render time. Don't do this.

Edit: btw, if that map structure for translucency slot, you borrowed from my scene, you may want to replace it by something else. I did it in hurry and i don't think it's suitable in this situation. I feel guilty for this :]

You are right bro! Thanks for catching that. It reduced the render time, and it looks good. Ok, I'll replace the map in the translucency.
Title: Re: tree Translucency
Post by: racoonart on 2014-02-17, 20:44:42
You can save a LOT of time by instancing maps as much as possible in shadertrees and different slots of a single material.

How is that technically? What are the drawbacks of non-instanced but identical bitmap maps? I never really thought about it since I try to instance as much as possible but is each non-instanced bitmap loaded separately into RAM (I can hardly imagine that) or is it just the internal overhead that is produced by multiple bitmap loaders?
Title: Re: tree Translucency
Post by: Ondra on 2014-02-17, 20:50:09
You can save a LOT of time by instancing maps as much as possible in shadertrees and different slots of a single material.

How is that technically? What are the drawbacks of non-instanced but identical bitmap maps? I never really thought about it since I try to instance as much as possible but is each non-instanced bitmap loaded separately into RAM (I can hardly imagine that) or is it just the internal overhead that is produced by multiple bitmap loaders?

Each map is not loaded into RAM separately, but each map is sampled separately if they are not instanced. 3dsmax actually has a caching mechanism implemented that allows reusing the first instance result for all subsequent ones. So instancing single map 4 times can make your shader evaluation 4 times faster.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 21:14:02
How does this look now? I change the translucency map.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 21:18:14
You can save a LOT of time by instancing maps as much as possible in shadertrees and different slots of a single material.

How is that technically? What are the drawbacks of non-instanced but identical bitmap maps? I never really thought about it since I try to instance as much as possible but is each non-instanced bitmap loaded separately into RAM (I can hardly imagine that) or is it just the internal overhead that is produced by multiple bitmap loaders?

Each map is not loaded into RAM separately, but each map is sampled separately if they are not instanced. 3dsmax actually has a caching mechanism implemented that allows reusing the first instance result for all subsequent ones. So instancing single map 4 times can make your shader evaluation 4 times faster.

yep, yep.
Title: Re: tree Translucency
Post by: romullus on 2014-02-17, 21:20:46
I think it's time to introduce front/back map to you. Right now, sun facing sides of your leaves, have way to much translucency, while back faces looks ok.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 21:30:42
I think it's time to introduce front/back map to you. Right now, sun facing sides of your leaves, have way to much translucency, while back faces looks ok.

Like this, you mean?
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 21:35:30
Or like this?
Title: Re: tree Translucency
Post by: vkiuru on 2014-02-17, 21:46:35
Here's a quick render of my current WIP project. Say what you will but I like strong colors in nature :) Worth mentioning is I live in Finland, our summers are short but vibrant in color whereas I think in places where there is more heat leaves often tend to look kinda dry, so I think geographical location might be one reason why we sometimes get conflicting opinions on saturation.

(http://i.imgur.com/cv9r6Ou.jpg)
Title: Re: tree Translucency
Post by: romullus on 2014-02-17, 22:36:25
Or like this?
Yep, something like this, just make sure your front facing map is darker, have more contrast and green color. Back facing may be more towards yellow, lighter with less contrast. Then you should have pretty good starting point.

Edit: whether your material's diffuse component needs twosided map or not, depends on type of leaves you trying to replicate.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 22:52:11
Here's a quick render of my current WIP project. Say what you will but I like strong colors in nature :) Worth mentioning is I live in Finland, our summers are short but vibrant in color whereas I think in places where there is more heat leaves often tend to look kinda dry, so I think geographical location might be one reason why we sometimes get conflicting opinions on saturation.

(http://i.imgur.com/cv9r6Ou.jpg)

Looks good man! I wouldn't change a thing. i think the most important thing in vegetation is translucency, and about color, there is millions of shades of green. I think you cant go wrong. My trees in my back yard are lime green in April and dull in late summer.
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-17, 22:57:54
Or like this?
Yep, something like this, just make sure your front facing map is darker, have more contrast and green color. Back facing may be more towards yellow, lighter with less contrast. Then you should have pretty good starting point.

Edit: whether your material's diffuse component needs twosided map or not, depends on type of leaves you trying to replicate.

Awsome, thanks!
Title: Re: tree Translucency
Post by: jjduncs on 2014-02-24, 15:34:33
jumping on the tree material testing bandwagon
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-24, 18:42:06
These look pretty cool! especially that maple tree. This is a never ending ride on the van wagon, with trees and all. Your slate view is cut off, can we see more to the right? Thanks
Title: Re: tree Translucency
Post by: jjduncs on 2014-02-26, 07:55:03
Yeah sorry about that. Its just connected to a multisub with all the different leaf mats (just different maps and colours). All the leaves use the same rough settings at the moment.
Title: Re: tree Translucency
Post by: Caue Rodrigues on 2014-02-26, 20:41:25
I tested the tips and had this result:

little tree in center

(https://dl.dropboxusercontent.com/u/16366319/Imagens_Foruns/cam_1.jpg)
Title: Re: tree Translucency
Post by: Alex Abarca on 2014-02-27, 21:08:12
It looks good!, I'm glad this discussion worked for you.
Title: Re: tree Translucency
Post by: Utroll on 2014-03-01, 06:46:56
+1
Title: Re: tree Translucency
Post by: jjduncs on 2014-03-01, 07:57:34
had a go with the same material as i posted earlier on a bunch of evermotion vol 58 trees.