Digital Art Zone

Basically it means that the renderer doesn’t take shortcuts to figure out how light bounces around in a scene. This is why an unbiased renderer seems to go forever, it keeps chasing those elusive light bounces pass after pass vs a biased renderer which works on the assumption that some limit should be put on how many times light will bounce around before calculating the effect of said light. The full explanation is a bit more involved ofc.

Poser and DAZ Studio’s built in renderers are examples of biased renderers, LUX (Reality plugin) and Octane are examples of unbiased renderers.

Unbiased Rendering - http://en.wikipedia.org/wiki/Unbiased_rendering

Gedd - 18 September 2012 06:01 AM

Basically it means that the renderer doesn’t take shortcuts to figure out how light bounces around in a scene. This is why an unbiased renderer seems to go forever, it keeps chasing those elusive light bounces pass after pass vs a biased renderer which works on the assumption that some limit should be put on how many times light will bounce around before calculating the effect of said light. The full explanation is a bit more involved ofc.

Poser and DAZ Studio’s built in renderers are examples of biased renderers, LUX (Reality plugin) and Octane are examples of unbiased renderers.

So that’s why then as Mattymanx said that the rendering just goes on & on until we decide to stop it. Is that correct? It just keeps chasing the light bouncing around until we decide to stop it.

So what if the user doesn’t step in & stop it and it goes on for several more days? Would it become like an old school darkroom print that if left in the developing chemical tray would just get darker & more dense? Or would it get lighter & lighter to the point of being washed out?

Neither.  Exposure remains the same.

the end user sets the exposure and lighting levels.  Letting it render forever only means its collecting more data.  And depending on the image depends on how much time is required.

Attached are 3 images showing different stages of this final render - http://mattymanx.deviantart.com/art/Reality-172311049 - The final render was around 9 hours I think.  I dont remember but I let it render while I slept but before I went to bed I grabbed a few copies.  In order they are 6min, 60min and 120min just to give you an idea of how it looked.  Plus the 6 min render will show you just how soon you can see stuff in the render though that is more dependant on total samples per pixel and not time.  But you dont have to wait until its done to get an idea of what you have.

Please note that I choose to adjust my exposure while it was rendering so the 6min copy is a bit darker.

Thanks Mattymanx. The first one obviously looks grainy and the latter 2 are much better.

I’d like to see the 9 hour render mark final image if you don’t mind.

But I’m also puzzled. Why did the one of the blonde bikini girl with the big head take 60 hours when all it had was a very simple black background and just one light used?

Seems this race car image has a lot more going on with lighting & surrounding environment. Was the image size much bigger with the Salome pic?

I linked to the final render is in the text.  Its the link to DeviantART.

As for the Salome image, she is standing in side a cube so the light never stops bouncing around and her skin and hair are set to the glossy material and glossy surfaces, including metal and mirror cause even more light bounce and thus longer render times.  Thats the laymans explanation.

I’ve heard people say that the LUX renderer doesn’t ever finish, not sure if it’s true or not. At the Octane site they made a point that people think the same of the Octane but that the Octane renderer will finally reach a conclusion. It will just take a long time in some cases. They didn’t clarify beyond that however. LUX being a different engine will act differently in some ways.

Oh, forgot to say.. Beautiful pictures Matty…

Mattymanx - 18 September 2012 04:51 PM

I linked to the final render is in the text.  Its the link to DeviantART.

As for the Salome image, she is standing in side a cube so the light never stops bouncing around and her skin and hair are set to the glossy material and glossy surfaces, including metal and mirror cause even more light bounce and thus longer render times.  Thats the laymans explanation.

Sorry Mattymanx, brain fart on my part. I never clicked the link to the DA page. One of those “Well, Duh!!” kind of things. It would pay me to pay attention wouldn’t it? That scene looks great!

Thanks for the reply and explanation. But for Salome, was there a reason to put her inside a cube? Pardon more noob questions, but what was the purpose of a cube? I never saw it in the scene. And the matter about indefinite rendering with no end still has me puzzled. If you had let the race car render for 9 additional hours, would it have looked significantly better than it did in the DA gallery. What would 9,12, 24, 48 more hours have done for it? Ditto for the girl. Would 60 more hours result in a 2X better render? It looked very finished already.

My two cents here.

To get realistic renders you must understand your render engine. There’s a lot of crappy renders with Lux because people don’t tweak their shaders and materials properly. Lux has spectral lightning and makes calculations based on real physical measurements which helps but thats not always enough espescially for skin. The advantage of Lux is that there is a material database that can be usefull

To understand lightning you can read in the Yafaray docs here

I prefer Yafaray as a render engine even if it has some bugs and still missing some functions like SSS

MarkR151 - 18 September 2012 10:53 PM

Mattymanx - 18 September 2012 04:51 PM

I linked to the final render is in the text.  Its the link to DeviantART.

As for the Salome image, she is standing in side a cube so the light never stops bouncing around and her skin and hair are set to the glossy material and glossy surfaces, including metal and mirror cause even more light bounce and thus longer render times.  Thats the laymans explanation.

Sorry Mattymanx, brain fart on my part. I never clicked the link to the DA page. One of those “Well, Duh!!” kind of things. It would pay me to pay attention wouldn’t it? That scene looks great!

Thanks for the reply and explanation. But for Salome, was there a reason to put her inside a cube? Pardon more noob questions, but what was the purpose of a cube? I never saw it in the scene. And the matter about indefinite rendering with no end still has me puzzled. If you had let the race car render for 9 additional hours, would it have looked significantly better than it did in the DA gallery. What would 9,12, 24, 48 more hours have done for it? Ditto for the girl. Would 60 more hours result in a 2X better render? It looked very finished already.

The purpose for the cube was so I could have the light bounce.  In the real world, light has something to bounce off of all time.  In a 3D program we can give the illution that the figure is in a room all the while they are really in an open space and you wont get the proper illumination all around the figure cause light escapes off in to nothing.

As for never ending and more samples, through Reality, you can tell Lux to stop when a certain amount of samples per pixel is reached.  But to my knowledge, Lux will never stop if you dont tell it to.  Its true that you want more samples for you image to make it look better but you will reach a point where you cannot see the difference.  This image here - http://mattymanx.deviantart.com/art/Jazlyn-321987986 - if I did not say so in the comments, you would not have guessed that I let it go up to 12,000 sample per pixel.  And I can tell you that I saw no real difference between it and the 3000 version.  I think I only let it run that high for fun.

Takeo.Kensei - 19 September 2012 12:22 AM

...you can read in the Yafaray docs here...

I glanced at the site and it looks like some good information there (bookmarked.) What is it you like about Yafaray btw?

Try this for size. Its an Octane render

http://www.youtube.com/watch?v=m-0T5EaMGmg

Gedd - 19 September 2012 11:07 AM

Takeo.Kensei - 19 September 2012 12:22 AM

...you can read in the Yafaray docs here...

I glanced at the site and it looks like some good information there (bookmarked.) What is it you like about Yafaray btw?

Yafaray is like the free little brother of Vray and if you have a look at their galleries that’s very good. Lightning is more intuitive as in 3delight, pretty much like Lux, but it’s quicker and I don’t need to buy some big graphic card to use it. There are also some options like sunsky, sun and IES light. There’s just no plugin for DAZ and you have to rework the materials

Some of you mentioned that UberEnvironment comes with Daz3D pro. I’m using Daz3d 4.5 and I do not see it. I checked plugins and its not even shown there. Yeah, I’m a bit of a idiot when it comes to Daz studio. So I do not know much about it. So can some one please enlighten me?

Regards

Edit: I think I found out how to use it!