Welcome to Antonio's Portfolio

The Home Section it's dedicated to general VFX subject.
To view my works please click in one of the tabs above.
I am responsible for modeling, texturing, shading, lighting, rendering and compositing.
Thanks for visiting, I hope you enjoy.

Monday, April 6, 2015

Renders Comparison part 2

Ok I finished some roughly tests to see how each render perform in a large scale scene.
This scene was an fbx file provided by Rodrigo Albano, an architect and great friend of mine.
I had the freedom to change a few things there, like some furniture downloaded from internet.
It has a little bit over 3.1 millions polygons, around 45 lights distributed over the ceiling(tray ceiling), under light shapes geo, and 1 HDR(shot at night) used in the light for the Sky, that illuminates the apartment by passing through windows with glass and open doors on the left side of the picture and a glass door behind the camera... And more then 100 shaders.
From one render to another I converted the shaders and lights as best as I could, trying to match same values in terms of color, glossiness/roughness, and light intensity, size, position etc... using a script that I wrote for this...
The renders settings for each of them was following the same process like in the simple scene test article that I wrote. If you didn't read that one, I high recommend you read it first to undestand the methodology used to make a fair compararison between them, so here's the link:
The only difference is that I raised the AA subdivds to 10 = 100samples and shaders, lights, GI samples to 2=400, max 800samples.
So here are the results:

For Vray everything is straight forward, and the Vray-RT running in IPR mode was fast an crucial to easily have some interior light mood for a night scene that we do have in real life. The default shaders of the scene was all phongs, and I converted them really quickly to the standard Vray material VrayMtl... I added in Camera DOF, and a Vray Fur in the carpet with a VrayHair shader, I couldn't make the default maya fur to work I am not very into it.  I also used a VraySSSkin shader to the dragon statue on the right side of the picture.
The render came fast after hitting render. And after 1 hour and 11 min it was done. There is a bit of noise in the ceiling from the GI for sure and some white speckles here and there from the DOF, but the overall is good and consistent.

The render took some minutes to be compiled/translated and then after that it really starts to "spit" the pixels to the Image Tool Screen.
Renderman Lights has only exposure feature to control the light intensity, so the light intensity may not match at some points, getting underexposure at some point and overexposure at others...
Also considering Renderman doesn't not have it's own fur system, I couldn't use any fur on the carpet, and I couldn't find a way to use the DOF in camera as well...
The shaders have been converted from the vray scene one to PxrDisney, PxrMetal, PxrGlass, and PxrSkin.
After renders is done, we still see noise in the ceiling where it is illuminated mainly by the indirect illumination(GI)...

In Arnold, I couldn't figure out what was causing the super green color in the right side of the picture, for this scene I am using alShaders for everything, including the dragon statue in the right side(remember that the aLShader has SSS builtin)  and there is colors above one where you would see the visible lights, so ignoring those things we have an initial render time to compile/translate the scene a bit faster than Renderman, but still more slowly then Vray...
There was some DOF in camera but since I didn't render all we can see very much how it was. I couldn't use fur for the same reasons as in Renderman.
The render took more than 10h to render 22% of it, so I had to hit cancel because does not worth conclude it for this test... Whatever I am trying to prove by comparison here, is now pretty obvious... but the part in the center that get complete rendered is very clean and have a nice result and to be honest I was not expecting that render time so high! I was imagine something 4 times more the V-ray render like in the simple scene test. I double checked each thing in the scene, and couldn't figure out why that render time so enormously, every sample was right in the lights, shaders, render settings. The geos was all good with their normal and stuff, because I had checked as soon as I put my hands on them, and I fixed whatever imperfection I spot on, so considering the other renders get a decent render time, I really don't understand what happened here. Without the object or even with just one shader for everything, and deleted a few lights near that region, disable the DOF and the green thing still persist... Even at this setup to conclude 6% of render it took roughly 2h... So from past test using Arnold, we may say well it doesn't need 2 samples for light and for the diffuse, glossy, refraction and SSS render sampling, because Arnold cleanup super well with less than that, maybe you should not even need AA 10 because you not using textures at this test, only the DOF in camera... Well you're right in say that, and that could probably make the render drop 2-4 times,  so if that drops 5x let's say, the 22% that took me 10h would translate in 10h to render it 100% right? Well I guess so... Why not to take even lower, 4-6 AA only and rest is 1? Well AA 6 may do the job like the other ones, and have more reasonable time, but still high than the other I guess, but I have to say that at AA 4 the edges/shapes of your object look fuzzy/blurried, so your render will not look very define and crips as it should. I did this test with the simple scene once and the render time drop by half if I am not wrong, but the result was not acceptable... So in the end I beat if I cut all the "fat" Arnold may finish the render in the time I had presumed, something around 4x more then V-Ray, but if I do that, it means that I took more easily with him in terms of numbers considering that was the same settings I used for the others and it worked pretty decent...

Just to resume, we are not here to look at pretty picture, but looking forward to see an engine fire proof test, in this case for general things that we normally use in a daily basis scene. Not trying to compare this or that particularly support feature that the other render does not, as well not been picky in better looking things like for example this render does a better SSSkin shader or a displacement... Things like that could fall into a more "subject" realm that each person will have a different opinion about it...
Of course in this scene, some pipeline stuff get in my way, and I don't have time and patience to fine tuning 3 renders just for test... So I hope you understand that, instead of start to blame on me.
In the end what I was looking for is to compare the general behavior of each render in in most cases scenarios where the standard shader of each render are the shaders that are been used in the scene, I beliave that is what we normally have for most of our scenes in a daily-basis...
I thank you for your time in reading this "case study", for me it worth the try.

No comments:

Post a Comment