how can avoid rough edges behind transparency?

[ThirdEye]

switch the AA to best

[Sneaker]

I think this is more of a fresnel problem in combination with refraction.
Having checked on fresnel in transparency and using the fresnel shader in other channels
lead to these kind of artifacts.
I was able to minimize this exclusively using the fresnel shader in diffrent channels.
-Michael

[gildattack]

hi guys,
thanks for the quick reply.
ThirdEye, my AA settings are set to best
Sneaker, i did a quick test which is the following: i unchecked the fresnel option (below refraction) and instead i put the fresnel shader inside the texture channel (inside transparency) and the artifacting is gone. I will twick the settings a little bit though.

thanks,

[govinda]

I hate to comment when I don't know (or remember actually) the full story, but those two fresnels do different things. This was the subject of a Per Anders revelation a few years ago regarding the fact that the check-box fresnel and the shader known as fresnel have different reasons for being. Anyway, the best idea is to let your eye be your guide. If you lose something by removing a setting, then the better answer is to up your AA to 8x8. It's not unheard-of to go to 16x16, even for animation, but with such a simple scene I can't imagine getting anywhere near that.

[gildattack]

govinda,
thanks for your comments. I see now they do different things because i am not getting where i want. I will get my AA settings higher but i'm afraid it will be painfull to render. Time will tell, so i'll let you know.

[AAAron]

I hate to comment when I don't know (or remember actually) the full story, but those two fresnels do different things. This was the subject of a Per Anders revelation a few years ago regarding the fact that the check-box fresnel and the shader known as fresnel have different reasons for being.

This is something I would really like to get explained. :love:

[LucentDreams]

the checkbox fresnel is a special fesnel tha tlinks rflecitons and transparency, even if you have the reflection channel off it is reflecting (hance later verson of cinema offer a reflectivity setting under the fresnel option) it also uses a set falloff thats supposed to be physically correct where the fresnel shader is simple an angle of incidence to camera gradient.

[AAAron]

Thanks Kai! :thumbsup:

[AAAron]

Am I right to assume :curious: , that the normal fresnel (the shader one) only takes viewing angle into account (front back etc. depending on the settings), whereas the fresnel in the transparency channel affect rays from "there own perspective" wherever they hit the surface of the object and tell them how to behave?

[LucentDreams]

well the Fresnel shader is just an angle of incidence shader for the camera angle so 0-90 degrees angle of the surface to the camera. Since it uses a gradient the falloff of color can be changed by changing the interpolation type of the gradient and moving the knots and handles around.

The fresnel checkbox is also just an angle of incidence to the camera, so they are identical in their basic principle. the Fresnel checkbox has a set falloff though so you can't customize it. the other thing is that the fresnel checkbox activates its own reflections which means you are getting true raytraced reflections with it, and that the transition from reflection to transparent falloff identically.

[AAAron]

Thanks again Kai for the enlightment. :love:

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