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Hi to all,
I not understand this:

when i render a sheet of glass with a thickness of 10 cm I can see the shadow where the sun is behind the camera


but if i render the same scene with a different point of view the shadow of shhet of glass is not present


if I render magnifying glass the shadow is always present ...

The position of the sun is the same in both images ...

why the shadow in the first image is present and in the second image is not present for the sheet of glass ?

I use Maxwell Render 2.6.1 - the glass material is obtained with Wizard High Glass and the Attenution Distance is 999
the sampling level for al is about 8

I have to reach sampling level 22 or hight to have the same images

someone can explain if this is correct or is physical correct ?

thanks

bye bye

Tiziano Silvestri
Maxwell Render dot IT staff

The issue here is the refracted caustics (behind the glass) are going to take a very long time to resolve under those lighting conditions -- for information about these issues see this thread:

http://www.maxwellrender.com/forum/view ... p?p=340525

As you have already noticed the issue is partially where the light is -- if it's behind the glass then everything is good... however if it's not then be prepared for very long waits to get accurate results.

A few things that can help:

1) rougher glass will solver these caustics faster (but still take a long time).
2) more diffuse lighting will help -- the sun is a very intense and very small light source so it generates very high contrast lighting, this in turn makes nice looking caustics but hard to solve behind the glass.
3) Use AGS for panes of Glass, it solves much faster and will look about the same for windows -- I particularly like the "Clear AGS" from the wizard.

BTW, to me this is the most pressing issue for future development of Maxwell (and unbiased rendering in general) -- Dielectrics are not a feature if they are unusable (in most practical senses).

Best,
Jason.

This is the same image at Sampling Level 22 !!
the shadow is always present in sheet of glass



Why is present ?

bye bye

Tiziano Silvestri
Maxwell Render dot IT staff

OK.

I Think that this is a limit or a mathematical insolution.

bye bye to all

Tiziano Silvestri
Maxwell Render dot IT staff

Where are U goin' ?

And you ?

I stay here , but You said bye bye all ergo I assumed you are leaving us for good .
then I asked wherae are You going, but I am not too fluently in english