as shown in the screenshot above, the water for a crystal bottle i am making, keeps getting these weird black areas, and the top part is always dark and black, what can i do to prevent this, or is this normal?
If I understand correctly there is a random number of samples that blender takes that is going to be between the min and the max that you set. Raise these numbers (currently 128 to 8 for transparency and 128 to 3 for bounces! which is low IMO) to see if it resolves that area. I have sometimes had to set Min and Max to the same to force a particular number of samples.
You might try reducing the IOR a bit to relieve the light stress as well. A little Black at the edges of very high IOR objects is realistic but not as solidly as you have in your image.
Sorry, I was looking at the top part of your picture! For the bottom it looks like a material problem maybe you could post a blend file.
I tried what you said as to the transmission and bounce levelsw, and it didnt work.
i removed the bottle to keep it from being distributed, it isnt that i dont trust the blenderartist forum, it is that i dont know the blenderartist forum.
Crystal Bottle Example Render Scene postable.blend (736 KB)
i dont think my reply made it through to this post, i think it was turned into a whole new post.
i tried what you suggested, but it didnt work.
i am removing the bottle, because i dont want it distributed, it isnt that i dont trust blenderartist forum, it is that i dont know the blenderartist forum.
alright so my last two replies didnt seem to make it, i dont think. i tried your suggestion and it didnt work.
Crystal Bottle Example Render Scene postable.blend (736 KB)
oops, i think its obvious im new here, sorry.
Is that the cgcookie ubershader? I am not sure if it’s ever necessary to use such a complicated shader but they are the experts! And you may actually have made it yourself so you know what’s going on with it. However it’s almost impossible for anyone except the maker and someone being paid by the hour to troubleshoot something like that! :spin:
Consider using a simpler shader?
Anyway your main problem is that you are not paying attention to your normals. Your black areas were probably due to this. In edit mode turn on normal and see which way they are pointing. Recalculate normal and flip normal from the toolshelf fix these problems. Note that if your surfaces intersect other surfaces (as in when you plop this into your bottle) Blender may not be able to figure out the shading order and this is also rendered as black speckles…
Also when you subsurf a ‘liquid’ volume note that the meniscus is probably curved in the wrong direction. Depending on your liquid this can have much more effect on the believability than any ultracomplicated shader.
I have rendered a small selection of low res demos …
Refractionsamples.blend (1.18 MB)
seems to be working
see pic
but would a lot easier if you use normal glass node!
for uber shader which is not included yet
ask the guy who design it
he might tell you what is wrong with your set up
dont’ forget to increase your samples to at least 50 to 100 for glass!
happy cycles
the supershader i made is pretty much the exact same thing as the uber shader, i constructed it while watching the tutorial, i dont think thee is anything wrong with it ill take a look at your .blend druban.
well, i followed drubans advice and it fixed it, but i now want to know if it looks like water and if i need to fix anything else.
i would also like to know a few things about the node setup i saw, i see this alot but dont know why, why was the glossy and transparent shader being mixed, isnt glass the same thing, and why was fesnel plugged into the fac?
ricky, yours does show the correct normals, but without the refraction, it looks almost invisible inside the glass
Looks like a little too refractive for water but not far off. Your decanter is much too thin walled for earth gravity :evilgrin: anyway these things are hard to separate, right, the container and the contents are evaluated together in the mind. So it might be that if you thicken the walls th water will look really too refractive…
Not sure which material you are referring to. The four materials I showed you used no transparent shaders. I was kind of pointing out that the glass shader and the glossy/refractive combo have quite the same effect, except the surface reflection is controllable with the fresnel factor used to blend the 2 by cheating and using a higher IOR.
If you are talking about the UBERSHADER (drumroll) I am afraid my attention span was not up to following the shader through all its tricks. It’s a character defect, I’m afraid.
ah, well this thread has certainly been solved otherwise, so thank you for all your help, and happy blending.
not certain here but your new uber shader is crashing my PC on latet SVN!
so i prefer to use the old nodes and control whatever i can !
for the liquid hope you added another mat inside i hope!
thanks
happy cycles