Advices in Church's Ando render

[pnavarra]

Hi,
Here his my first render with church's Ando model.


How to smooth the reflect in walls for exemple?
Here are my options :




Cheers.

[dalomar_cg]

Re: Advices in Church's Ando render

There are two things that I think will help. I broke them down into sections since I kind of already wrote them...

Section 1
The big issue is actually your adaptive amount. An adaptive amount of 1 is not very good for dark areas, as it causes a gross underplacement of irradiance map samples, which can't be overcome with other settings. I'd say set it to at least .95, but .9 really would be better (for IR purposes, but .95 would probably be better overall).

The second issue is more with your irradiance map settings. It this case you'll need more hemispheric subdivisions (step it up to something like 80). You also have a max rate of 1, which in my opinion is not very efficient (ie too much time for not much return on quality). Your time will be better spend calculating with more subdivisions then a higher max rate, so I'd decrease that to -1 (or 0 if you really want)


Section 2
There's also some subdivisions issues with the walls, which may actually be better served by having some better antialiasing. Adaptive Subdivision is really only good to a certain point (the point your at now), but from that point on Adaptive QMC is going to allow you to get smoother results (try 1-18 and go from there). If you do that you might want to clamp the output as to prevent oversampling in the very bright parts of the window.

As a more general thing, I believe Jorge set up the tutorial with a single big light around the cross. Its better subdivisions wise to just create 2 kinda thin rec lights in the cross rather then one huge light. This will get a better subdivision placement

[pnavarra]

Re: Advices in Church's Ando render

Hi dalomar,

First, many thks for your answer wich is very serious and clear.
This morning, I'm trying to applicate your advices and I'll put my result.
In parallel, I'm reading the Vray Doc.pdf

Cheers.

[kwistenbiebel1]

Re: Advices in Church's Ando render

I like these kind of threads. ;D
An image post side by side with the settings and a reply from Dalomar with suggestions for improvements.

Very educational. Thanks.

Biebel

[pnavarra]

Re: Advices in Church's Ando render

Ok, here is the last render :


New parameters :
Adaptive QMC Max Subdiv : 100
QMC Sampler Adaptive Amount : 0.9
Irradiance Map : -3 to 0 (but it's true, -1 done same result)
Subdivs : 200
Light Cache : Subdiv : 1000 ans Num Phases 4





My opinion :
A bit dark (what about changing ISO or Shutter speed)?
(By the way, does the ISO, like in real, adds grains?)
And stil not sweet I think

What do you think?

Cheers

[dalomar_cg]

Re: Advices in Church's Ando render

First off, changing the camera settings are a very good way to change the illumination levels. Also, you get the gold star of the day for knowing that film grain is associated with ISO. With V-Ray, there is no side effects of using a higher ISO, so go for setting that however you'd like (technically, there is no side effects with any other settings since DOF and Moblur don't work with the physical camera yet).

So now for stage two of adjusting the settings. This time I'll do it by rollout sections

LC...
The one setting that I always recommend having enabled is to Use For Glossy Rays...it should help speed up the glossy reflection calculations. Another thing that I recommend is to decrease the sample size to .01 (at a larger resolution .005 might be good). This should help get more detail. Other note, number of phases should correspond to the number of processor threads

IR...
I haven't seen a need for 200 subDs... 120 should be fine. If you want you can try stretching the max rate to -1

Materials...
Now you can start adding a few more subdivisions on the materials themselves. by default they are at 8, so try setting them to like 10-12 and that should be enough to smooth it out (especially with those AA settings)

BTW Thanks biebel

[pnavarra]

Re: Advices in Church's Ando render

Dolomar,

Also, you get the gold star of the day for knowing that film grain is associated with ISO..

I make some photo, that's normal to know that. Anyway, thx

I've noticed your new advices and starting a new render tonight.

Cheers.

[dalomar_cg]

Re: Advices in Church's Ando render

Yea the ISO grain thing is only going to be something that you'll know if you do some photography, which is something I think is undervalued within computer graphics/rendering (I feel it makes the concept of light more "real", among other things). To most people who only ever use point and click cameras, exposure isn't something that crosses their mind. But if that is something that you've dealt with, then using the physical camera becomes a much more intuitive control because it becomes about how you're capturing the light as opposed to setting the correct levels of the light... just my rambling.

[pnavarra]

Re: Advices in Church's Ando render

which is something I think is undervalued within computer graphics/rendering (I feel it makes the concept of light more "real", among other things)

You're right!

Still talking about this subject, what about the Focal-Number?
Normaly, a short focal (5.6 for exemple) reduce the sharp zone around the focal center point. And a heigher focal increase the sharp zone and the exposure time must be heigher...What about Pysical Cam in Vray?

Monday, I'll put a new render with new settings.

Have a nice week-end.
Cheers

BTW : Hope you'll xcuse my poor english from france.

[dalomar_cg]

Re: Advices in Church's Ando render

The relationships between F-Stop, Shutter Speed, and ISO are going to be relatively the same as a real camera...so having a high f-stop will require a longer exposure time. Currently, because DOF is not working with the physical camera, there won't be any blurring/sharpness associated with the f-stop, but hopefully that will get worked out soon.

[pnavarra]

Re: Advices in Church's Ando render

Hi, here is the last render :


And here are the options




What else?
If someone wants the model...I can upload it.

Cheers.

[huyvu]

Re: Advices in Church's Ando render

hello , could you upload the sketchup file of this topic ? thanks.

[Fakircho]

Re: Advices in Church's Ando render

yes can you please post the skp file associated with the church of light tutorial

[Dangeroux]

Re: Advices in Church's Ando render

Here's a link to the skp file on the pushpullbar forums. You might need to register to download it though.

http://www.pushpullbar.com/forums//s...ead.php?t=2473

[pnavarra]

Re: Advices in Church's Ando render

Hi,
Sorry for answering late.
Here are the files :
- skp model in SUV6
- render vray options

http://www.youswap.com/index.php?dow...0-000b6a3d2c0b

Cheers.