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				Grass material
				Posted: Wed Nov 20, 2013 1:52 pm
				by medzo
				Hi!
Why Vray renders grass so much more realistic than Kray? This is especially noticable with close-ups.
Both renders are from Vray, I can't get even close with Kray. Any ideas?
 
			
					
				Re: Grass material
				Posted: Wed Nov 20, 2013 2:56 pm
				by Janusz Biela
				You can make the same in Kray. I do not see any problems.
The only one difference is: in V-ray you have special shader which simulate fast SSS.
But I doubt it is used in these renders (slow render).
Rest depends form user skill.  

 
			
					
				Re: Grass material
				Posted: Wed Nov 20, 2013 4:11 pm
				by medzo
				Well, first render shows double sided material, second has activated translucency inside standard material (hybrid mode+ greenish translucency color).
With Kray I was getting close with LW translucency shader pluged into diffuse shading, but it is painfully slow (150x200px took 45 minutes).
Don't get me wrong, with Kray I can make grass that is quite nice, but it is just not the same level of quality like Vray.
This is what i get straight from Kray
It can be improved in post production, but I dont think it reaches Vray quality
 
			
					
				Re: Grass material
				Posted: Thu Nov 21, 2013 12:54 am
				by 3dream
				So which image (top or bottom) is VRAY.  There are things about each that I like. Just curious.
			 
			
					
				Re: Grass material
				Posted: Thu Nov 21, 2013 9:44 am
				by Janusz Biela
				3dream wrote:So which image (top or bottom) is VRAY.  There are things about each that I like. Just curious.
First topic has two images from V-ray.
Medzo I think you should concentrate more with better surfacing (specular or reflection) + better light.
 
			
					
				Re: Grass material
				Posted: Thu Nov 21, 2013 12:40 pm
				by CHRIS.PI3
				Well I don't see any difference.Kray grass seems equal if not better.The lighting in the vray scene makes the difference.
			 
			
					
				Re: Grass material
				Posted: Sun Nov 24, 2013 4:15 pm
				by Keraressi Abdelkarim
				Easy in this sample scn u can acheive any render from vray with kray 2.5 and u can do more quality go pls take a look on janusz render he is thebest . With his skill and his crazy surfaces no vray artist included alex romain and so on cant produce janusz biela surfaces his own surfaces and his knewedge. Also u can acheive any photorealistic with kray. 

 
			
					
				Re: Grass material
				Posted: Tue Dec 10, 2013 10:17 pm
				by Janusz Biela
				Actually, problem with grass and leafs is very wide.
- problem with SSS (nobody even try simulate on big scale this effect)
- leaf material is one of the difficult material for simulate
- amount of physic in leafs is huge (SSS, transparency, reflection, bump, etc)
- the only way to render grass/leafs property is simulate it by mix of specularity, reflection and translucency
- in Kray we have only "simulation" of translucency from Lightwave is not that good as Fast SSS Shader in V-ray (I mean fast transport of light inside materials) this is only one missing part in Kray.Rest you can easily do by Nodes - for example: Double Translucency which is very important for leaf )not for grass!)
- very important is shape of leafs (it must looks naturally) Not too thin not too thick, not too curved not too straight. Random of seed by Instances must be also done very well - no repeating feeling.
- post process the top one (Yes! renders from V-ray also are ugly and only good post process can handle it)
- Sometimes nice looking close-up of grass doesn`t mean it must looks great in exteriors scene...sometimes is just artist expression with post process. 
- generally, I think, there are just a few people who knows how to render property grass and leafs...
- because we have all tools to render grass/leafs (except this unlucky shader for fast SSS) everything depends from our skill 
 
 
In free time I will try continue this topic because personally I also get mad about this material simulation  

 
			
					
				Re: Grass material
				Posted: Wed Dec 11, 2013 10:26 am
				by medzo
				Nice!
Could you show us raw render without post?
And material setup, please?
			 
			
					
				Re: Grass material
				Posted: Thu Dec 12, 2013 12:40 pm
				by Alexis
				Yes, very good render  

 
			
					
				Re: Grass material
				Posted: Mon Jan 27, 2014 10:13 pm
				by brainpolka
				My take on the grass close-up. With some DOF it will look sexy anyway  
 
The hard part is to make it look real on a big scale.
 
			
					
				Re: Grass material
				Posted: Mon Jan 27, 2014 10:58 pm
				by Janusz Biela
				I was waiting for refreshing post 

Here my tests (still in queue some ideas). Problem for me is that grass need quite strong post process and an idea how to show the render. It must be strong Dof, close-up, kind of strong saturated post...I do not like. Anyway in free time will render some new views.
 
			
					
				Re: Grass material
				Posted: Mon Jan 27, 2014 11:45 pm
				by brainpolka
				Haha yes. This will be an ongoing process for me now. Find the right grass!  

 
			
					
				Re: Grass material
				Posted: Tue Jan 28, 2014 8:42 am
				by Janusz Biela
				Try with this model from my renders.
			 
			
					
				Re: Grass material
				Posted: Tue Jan 28, 2014 3:33 pm
				by brainpolka
				Thanks!