Rendering 1.47.03 Scene in 1.5

[Adam H. Stewart]

Please see images above. The first one was rendered with 1.47.03 the second one was rendered using the exact same scene just opened and rendered in 1.5. There are many differences, I know the anti-alias settings need to be tweaked with 1.5 and there are some color mapping setting changes - but are there any material changes that would account for the vast differences between the two images?
I am a little freaked out by this - I have alot of scene's created in 1.47.03 that I have tweaked to death - I would die if I had to go back and re-tweak all my settings for 1.5. Maybe Vlado can put together a render preset that will bring the 1.5 settings back to a place that resembles a 1.47.03 set-up.

Thanks as always for your help.

[RErender]

There was a bug in the reflections/refractions in 1.47, not sure what it was exactly but 1.50 seems too preserve much more energy. Probably need to lower the reflection amount and raise the fog amount to match the old look.

[jacksc02]

does the boject have any SSS?

[Adam H. Stewart]

Material Properties



I won't lie to you this is a complex material - there are plenty of things that could be going wrong. Is it possible there is a gama shift happening somewhere that would affect my fall off ? How are 1.47.03 materials interprited by 1.5 ?
This being said I find is very disturbing that the who images side by side look so different. I was trying tests last night on some of my other scene's, they where luckily giving better results then this, but I still can't get to grips with the new Anti-alias paradime. I have been through alot of the posts and read the manual but I still don't get it.
It used to be so much simplier - what I have always loved about Vray was you didn't need to F@ck around with the AA settings that much - out of the box Adaptive worked 90% of the time - if you needed more just play around with min and maximum settings - now I can't even begin to tell you how confused I am Should I rollback to 1.47.03 or am I overacting ?

[vlado]

The AA issues *are* because of changes to the color mapping and the help index explains how to avoid them and what the whole issue is about. So you know how to avoid these.

As for the difference in the material, it looks to be mainly because of the different treatment for internal reflections. The 1.5 version should be more correct in that regard.

To test if the difference is indeed in the internal reflections, enable the refractions "exit color" option, set the max. depth for reflections and refractions to 2. This will disable the internal reflections. Next check if you get identical results in both versions. If yes, then the difference is indeed in those reflections.

I'll try to replicate the situation a bit later and see what happens.

Best regards,
Vlado

[vlado]

So, further investigation showed that the issue is the different treatment of the reflection map on internal (back) sides when "Reflect on back side" option is OFF.

In 1.47 builds, the reflection map was computed and was used to reduce the refraction color accordingly, even though the actual back-side reflections were not computed.

In 1.5, the reflection map is ignored and the full refraction color is used; no back-side reflections are computed.

The 1.5 approach is probably somewhat more logical, if you compare it to the action of the "Trace reflections" option, which behaves in the same way but for the normal reflections.

When "Reflect on back side" is ON, both builds produce very similar results.

Best regards,
Vlado