sree.arun.kr, thank you so much for finding out the eta / Ni issue. SunFlow doesn't seem to be able to handle values equal to 1. This value is found very often in MTL files and is actually wrong, because it matches the index of refraction in vacuum, definitively something not similar to a material!
I fixed this issue by forcing the eta value to a minimum of 1.33 (the index of refraction of the water).
And… it seems to fix (all?) the black dots problems, even black dots that appeared on furniture placed quite far from a piece of glass with a wrong Ni value. [:)]
Please, dear users, check it on your side with the Beta 18 that I just posted.


But I don't really understand the export to OBJ issue you mentioned in your message.
If it's because 3DS files are transformed in OBJ files in a .sh3d file, it's on purpose and I won't change it, but you can keep the 3DS file unchanged by importing a ZIP file containing it. If it's because you specified some index of refraction in the 3DS file you imported, don't expect to find this value in Sweet Home 3D, because it is stored and reexported only for OBJ files. If it's something else, post or [url=mailto:[email protected]]send me[/url] a way to reproduce it step by step.

[sree.arun.kr, you posted your last message while I was writing this one, I'm going to answer you afterwards]