here are some cycles nodes set up to see differences with refraction nodes
the first on left with transp + refrac
seems to be with no glossy at all almost like diffuse only !
are there way to see change reflection color ?
thanks
Here is a simple example. The ape to the left equals normal glass. In the middle the reflection color is different then refraction. To right: Four different colors for refraction/reflection on the front/back side.
one thing here
the base cube i cannot apply the mirror cause it is multiuser !
material is single user i think in cycles
how do you apply modifier here ?
be back with another test soon
thanks
did a test to check for some sort fo caustic
but cannot run it at 1000 samples it would take days to do this on CPU
refractestcaustic.blend (102 KB)
can these refracted rays make some sort of caustic or not?
also how do you make another copy of the group nodes
or make it single user ?
also what does the normal inputs do in this case ?
thanks
Anything inside a node group is linked/shared and should stay that way. Only make it a single user if you change the internal setup.
Anything outside (for example input sockets and their values) is not and can have different settings from material to material.
If you are familiar with object oriented programming then think about the node group edit mode as the class definition and the actual node inside a setup as an instance of that class (the actual object) to which you can assign different values.
but how do you get another independant group?
like having different colors for a model then make another model with other colors?
also if i change the group color inputs it does not change anything ?
thanks
There are caustics. But they are very week in your light setup (big lights, caustics need sharp/bright small lamps) and i set “clamp” to 5. Set it to zero (disables clamping) and you will get much stronger caustics, but also a lot more noise, because Cycles (unidirectional pathtracing in general) is really bad at caustics and clamping basically suppresses only the caustics.
this is clamp in render panel
what does it do i forgot !
i tried to boost it with a lightpath but it changes everything else too!
if you put a spot light above object it should help for caustic?
i tried it but cycles spot light don’t work ?
have to get another SVN
this seems to rely strongly on the backface
and may be normal !
any explanations for this effect ?
thanks
Cycles does not support spotlights. You will just have to scale down the light planes and increase the brightness of the lamps. But the brigther and smaller lamps are the more noise you will have.
Clamp reduces the brightness of every sample to a maximum (the clamp value) before it is merged down to the film. Caustics are seldom and usually very bright to compensate their seldom appearance. Thats also why they produce a lot of noise, even so they are correct that way and it isn’t really noise at all. The downside is that they need a huge amount of samples before they don’t look like noise and merge with the rest. Especially path tracing produces them very seldom and they have to be very bright --> lot of samples needed. Really wished that cycles would have a more intelligent method for caustics.
spot light works for a few weeks already in cycles!
but i think my angle was way too small and not certain light pass well though glass or refraction node!
would be easier if i could boost it with lightpath
but not easy to add on this node set up!
i’ll test some more!
thanks
i tried to manually change the group color input and it does not work!
need to add a mix shader to set it
this looks like a bug can you confirm
can you show the nodes set up for subtract refraction might be interesting too!
thanks