Rendering is very slow on external windows

[liorsturlesi]

Hi,

Can anyone tell me why the rendering buckets are having so much hard time rendering the window glass. It's taking very long for vray to process these ares in the frame.

 

Would like to know why, and how can i make it faster to render ?

[Scott Schroeder]

Screencaps of your render settings, material settings, and the render would be awful helpful here. Other than that, you are going to get random guesses or no responses at all.

[Morne Erasmus]

+1 What Scott said. It can be a couple of different things.

 

1st Guess would be something to do with your refraction. Either you have your refraction gloss less than 1.0, or maybe affect shadows are unticked in which case the light won't properly go through the glass in you may even see splotches inside.

 

Post your settings so we can give a more informed answer

[liorsturlesi]

Hi guys,

Here is a snapshot. Nothing really special....

[Morne Erasmus]

Oh ok you're looking out where I thought maybe you were looking in. What are you using to light the exterior?

The AA is more than likely having a hard time to work through the high contrast between light and dark pixels on the outside. The sky might be very bright and then suddenly you have a leave or whatever that is darker.

 

Couple if things you can do here, adjust your AA for example

If you don't care much about a 100% correct LWF then you can use reinhard and set your burn on 0.05 and leave the mode on "None (don't apply anyting)"

[liorsturlesi]

Thanks Erasmus,

The AA is 1/6, and you might be right about the dark and bright differences.

Should i raise the AA ?

I'm already using the Reinhard with 0.6 on burn value...

[murphz]

Hi Lior S,

 

You have a lot of foliage in your exterior and my guess it is the AA sampling of this+the refraction of the windows that is giving you access render times.

Vlado (Vray) recently added a subdivs mulitlplier as an addition to the already GI subdivs mulitlplier to get around this with the latest update

of VRay 3.1

 

 

You simply select the trees and reduces the subdivs amount. you notice very little to no difference in output but render times are reduced dramatically..play with it until you find the right balance.

My guess is that you working from Vray 2.0 ? A hack around this is to create two sets of lights. One with the higher sub-divs and one with a low sub divs..go as low as one for a base test and then exclude the tress from the lights with the higher sub divs and render the tress with the lower set using the include function remembering to exclude everything else. It sounds like a lot of work is easily set up.

Also in your render elements select sample rate and you should see that your windows at the minute are all red, which means your AA is having to do a lot of work = long render times... as your playing with the settings in the suggestion above you should see the color become less hot and more blues and greens should be the dominent color. Lets us know how it goes

[murphz]

Hi Lior S,

 

You have a lot of foliage in your exterior and my guess it is the AA sampling of this+the refraction of the windows that is giving you access render times.

Vlado (Vray) recently added a subdivs mulitlplier as an addition to the already GI subdivs mulitlplier to get around this with the latest update

of VRay 3.1

 

http://i1290.photobucket.com/albums/b539/PeteMac1980/Global-subs-Vlado_zps7vfz3e6i.jpg

 

You simply select the trees and reduces the subdivs amount. you notice very little to no difference in output but render times are reduced dramatically..play

 

with it until you find the right balance.

My guess is that you working from Vray 2.0 ? A hack around this is to create two sets of lights. One with the higher sub-divs and one with a low sub divs..go

 

as low as one for a base test and then exclude the tress from the higher lights with the higher sub divs and render with the lower set. It sounds like a lot

 

of work is easily set up.

Also in your render elements select sample rate and you should see that your windows at the minute are all red, which means your AA is having to do a lot of

 

work = long render times... as your playing with the settings in the suggestion above you should see the color become less hot and more blues and greens

 

should be the dominent color. Lets us know how it goes

[murphz]

Hi Lior S,

 

You have a lot of foliage in your exterior and my guess it is the AA sampling of this+the refraction of the windows that is giving you access render times.

Vlado (Vray) recently added a subdivision multiplier as an addition to the already implemented GI subdivision multiplier to get around this with the latest update of VRay 3.0.

 

You simply select the trees and reduces the subdivision amount. You notice very little to no difference in output but render times are reduced dramatically.Play with it until you find the right balance.

 

My guess is that you working from Vray 2.0 ? A hack around this is to create two sets of lights. One with higher subdivision that your currently using for final renders and one with low subdivision..go as low as one for a base test and then exclude the tress from the lights with the higher subdivision and render with the lower set, and vice versa for the low subdivision lights, exclude everything but the tress. It sounds like a lot of work but is easily set up.

 

Also in your render elements select sample rate and you should see that your windows at the minute are all red, which means your AA is having to do a lot of work = long render times.

As your playing with the settings in the suggestion above you should see the color become less hot and more blues and greens should be the dominant color. Lets us know how it goes

Edited April 2, 2015 by murphz

[liorsturlesi]

Hi Peter,

Ok i will give it a try. I do pay a lot of attention to the sample rate pass, so I'll will take a good look at it again.

Thanks for the advice !