Glass bug? new medium solver?

[arqrenderz]

Hi, i encounter some thing, i think is a bug, attached a max file is a simple glass, if i put a value higher than 0 on the absorption color the glass turns completely black. the scale of the object is fine, if i disable the new medium solver the glass renders fine.

[romullus]

Did you check object normals? Are they oriented the "right" way?

[maru]

This will probably help: https://coronarenderer.freshdesk.com/support/solutions/articles/5000515618

[GeorgeK]

Hi, i encounter some thing, i think is a bug, attached a max file is a simple glass, if i put a value higher than 0 on the absorption color the glass turns completely black. the scale of the object is fine, if i disable the new medium solver the glass renders fine.

As far as I know 0 value is disabling the effect of absorption, any value depending on the unit setup of your 3ds max above 0, will result on defining the distance rays transfer in the medium, so a decimal of 0.1cm means your object has minimal light absorption. Raising the number towards object size to world-space relation your absorption will become more transparent.

I am guessing as a bug you are referring to the fact that your object has 0 reflectivity without the medium resolving, that's because your mesh has inverted normals. Just use normal modifier and invert or simply flip all faces/polygons in editable poly and your glass will work fine with no medium resolving :)