shadows questions

[tuna57]

I've been using TW for a three odd years now and have been pleased with my results. That being said I normally don't try for photo real effects. Usually render and then post pro to get a more illustrative look to my work. Just started messing about with some more realistic renders, glassware to be exact, prompted by a post of a fellow TW user.

Here's the question , Posted a pic of the same glass. Material settings the same for both renders. Sun settings the same also.

Glass on right rendered on medium setting took about 25 seconds.

Glass on left rendered on 08 exterior progressive. 200 passes.

The question is why the big difference in the shadows between the two renders. Been messing about for several nights with different bottles and glasses and getting the same shadow results.

On low and medium settings get the shadow on the right. On high and exterior getting the solid shadow. What am I missing. I assume the right shadow is more correct as liquid and glass aren't going to show a solid shadow. Is this just a matter of the higher settings have to run way more passes to resolve the shadow ? Your input will be appreciated.

[alvydas]

Exterior progressive does not calculating caustic from sun light .
Interior+ produce caustic shadows from sunlight... Interior progressive produce caustic only from HDR globals or mesh light source.
Along this way a good solution is to increase the value of the pseudo caustic. (Easy 01 - 07)

[tuna57]

alvydas , thanks for your reply. makes perfect sense now that you point it out. I guess I'll get back to my experiments.

[Fletch]

Alvydas is 100% correct.

In case you haven't seen it:
Subject: Liquid In A Glass - How To Model Wine or Water - by Massimo