Progressive path tracing renders

[dbuchhofer]

Is there any difference to this and simply using the QMC (brute force) type? its image quality was always great "eventually" if you let one finish this seems quite similar.

[Gijs]

Main difference is that with QMC method you need to set the amount of bounces and subdivisons. With this method infinite lightbounces are calculated and the main advantage is that the whole image is built up gradually.

[Pixelperfectg]

Main difference is that with QMC method you need to set the amount of bounces and subdivisons. With this method infinite lightbounces are calculated and the main advantage is that the whole image is built up gradually.

With that in mind, any recommendations as to what I should set my primary & secondary GI bounces to when using PPT? I've been adjusting the bounces in the tests I've posted here. (I've been using around 3 primary bounces, .75 secondary bounces)

[Pixelperfectg]

Here's a quick & dirty PPT daylight test. I had the subdivisions set at 750 as to keep the render times down (around one minute per frame).

This is using Dreamscape for the lighting (no VRay lights...just the one Dreamscape Sun). The GI color is coming from the DS atmosphere.

http://www.jeffpatton.net/cg-post/VRay-ppt-DS.avi

[jacksc02]

Good thread guys!
I did a test yesterday and I noticed that PPT has a hard time with refractive glossies and SSS.

Has anyone else had these problems?

I will try to post up an image soon.

[Geddart]

yes jacksc02, i noticed that too. It also does not work together with Matte Materials. I will prepare some Images too.

Nice Animation Jeff, but what's that flickering?

[Pixelperfectg]

Nice Animation Jeff, but what's that flickering?

It's my VRay...it keeps flickering on animations.....
(hehehe, JUST KIDDING GUYS)

Seriously, it's a silly bug in DS. I forgot to restart max before rendering the sequence. If you edit the DS clouds and render...the sky flickers....but if you edit the cloud settings then restart max and render...it works.

I didn't notice it until well into the render and I didn't feel like restarting it since it was just a test render anyway.

[Geddart]

HA! I had this bug too with Dreamscape but i didn't know what's causing this. (...and how to resolve it.) (Do you know if they want to fix that before Dreamscape3?)

Thanks a Lot Jeff!

[Pixelperfectg]

LOL. Yeah, over at the sitni-sati (sp?) forum, they mention a patch is coming (from Turbosquid)...so for now, I just have to keep remembering to reset 3dsmax before rendering with DS.

[Gijs]

With that in mind, any recommendations as to what I should set my primary & secondary GI bounces to when using PPT? I've been adjusting the bounces in the tests I've posted here. (I've been using around 3 primary bounces, .75 secondary bounces)

I assume those last numbers you mention are multipliers? The most physically correct is the default 1/1. But it could well be that using a lower multiplier for secondary bounces you get a faster solution. This may be worth a test.

[RErender]

a little test with displacement

[jacksc02]

What was the render time Eric?

Nice test BTW!!

[RErender]

It was 5 or 6 hrs when I stopped it.

[tom schuelke]

Did anyone of you allready try to use ppt only for secoundary bounces ?

does this work.

this would be a good method to get an immage with very simple caustix setup. if caustix stay with the imap.

Tom

[natty]

You can run PPT for say 10 mins then save the result as a lightcache.. then use that.