Glass material in Cycles!

Cycles is a great render engine,but I’m still facing problems with getting a clean and pure glass with no flakes or fireflies.So any tricks around well be great?

Thank you :slight_smile:

Turn off caustics.
If your glass is thin, use transparent + Glossy.

Thank you FreeMind but I’m rendering with no caustics and I tried to use the transparent + Glossy with an HDR image but the flakes still there!!

The only solution so far is to render for longer and then remove the hot pixels in a image-editing software.

Thank you NinthJake but I’ll keep trying to still inside Blender :wink:

you could try to mask out the solid white pixels and use some kind of blur?

(bluring the original image and masking it then)

(Not an expert here, someone might have a clearer idea how to make it :()

After the fact cleanup solutions are not really that helpful when dealing with animations. Sure, fixing up one frame in photoshop is ok, but when you have a thousand frames to cleanup the suggestion seems silly. Cycles needs to render clean at some point.

Thank you John.I’ll give it a try :slight_smile:

Your’e right and thank you a lot Atom :slight_smile:


considering that Cycles is a pathtracer I think your only option is longer rendering or getting a much faster PC if you want to work only inside Blender or need to render animations.

It sucks but I think there is honestly no other alternative to that right now - sadly.

Maybe at one point Cycles can be speed wise improved and also get an anti firefly tool.

Otherwise could Yafaray help? It has a very good material system as well and the renderer is powerful.
It lacks SSS motion blur and cannot save GI maps for reuse but as long as that is not needed by you
maybe it could offer a good alternative.

this is how much it can improve reducing noise (on the left plain, on the right denoising node in action):
notice i had to plug another glass shader with no IOR. this, of course returns incorrect caustics, but hey!

Yeah! YafaRay is one of the best raytracing rendering engines for Blender out there.Unlike the Unbiased rendering engine technologies the Raytracing technology still more stable and dandy for most users,but in my opinion the future is for the Unbiased engines.

Anyway thank you a lot cekuhnen :slight_smile:

Nice trick around and thank a lot you for sharing :wink:

Be sure you check the last blend in that thread, i made a modification to use masks (a checker pattern in that file) and also changed translucent with a colored transparent shader which speeds up everything, althought this hasn’t much to deal with glass and the need for caustics
btw it’s Lsscpp :slight_smile:

Just render it for eternity.

Thank you a lot for your support :slight_smile:

LOL!! I don’t have much time!

composite several renders with different seed values…fireflies will always be in different locations and you can always try using image cloning from one of the renders to paint out the fireflies from inside of blender.

Another alternative, simply create a new layer in your favorite paint program that uses additive blending and paint the caustics onto the image using the firefly clusters as a rough guide.

It can take a while to get right, but if it only covers part of the image, it is quicker than waiting for them to completely render out.

Seems daunting,but why not? We should try any trick out there! Thank you a lot Justin.