hi!

If i add a parameter node to export refraction, for using as image plane, the render slows down drastically.

If i delete the image plane, and the parameter node, it stays slow as hell.
If i put down a new glass shader it is much faster again.

Anyone bumped into this or has an idea what could this be?

Yeah, on linux I can repro this for a trivial example, I get render times of:

Render Time: 33.72u 0.38s 11.08r

before adding the refract layer. When I add it, it goes up to:

Render Time: 1:09.40u 0.52s 21.01r

after adding and stays that way after deleting the export and the extra layer on the ROP. Note that a restart ‘fixes’ it - it is arguably a bug, although I would be interested in the results of a non-trivial test. We output extra layers all the time and certainly haven't noticed a sudden huge hit on render times when adding them. This might be a ‘one time’ hit when exporting something other than RGBA, and the fact it hangs around for the rest of that session is either a quirk or a bug(even possibly by design for a reason we don't know).

Cheers,

J.C.

I hope someone from SESI will inspect this, anyway thanks for taking the time looking into the problem.

Don't forget actually sending the bug report to SESI, not just posting it here on the forum

reported.