FRESNEL

[talats]

Hi guys, could someone make a tutorial or explain how to use fresnel for opaque materials (non transparent materials) ? A tutorial explaining how to obtain the relationship between reflection and diffuseness?

To be sincer I am starting to be tired to set always incidence angle gradients. I really would like to do everything with a fresnel node, but, until now, I couldn't understaind how to work with that node and, more over, everything I found on the web always consider the relation between reflection and refraction (and it's good for transparent surfaces) but not how obtain the relation between reflection and diffuse.

Thanks a lot

Roberto

[Janusz Biela]

Try this. I use parametr 1.8 - 2.0 in fresnel + reflection map.
BASE DIFFUSE 0.9 for bright, 0.6 for very dark surfaces.

[jure]

Hi guys, could someone make a tutorial or explain how to use fresnel for opaque materials (non transparent materials) ? A tutorial explaining how to obtain the relationship between reflection and diffuseness?

To be sincer I am starting to be tired to set always incidence angle gradients. I really would like to do everything with a fresnel node, but, until now, I couldn't understaind how to work with that node and, more over, everything I found on the web always consider the relation between reflection and refraction (and it's good for transparent surfaces) but not how obtain the relation between reflection and diffuse.

Thanks a lot

Roberto

For non transparent materials I haven't found any table that would list IOR for common materials. However you can try and download some vray or maxwell material presets and look what values they use... For metals it tends to be a high value... 10-20. Other materials have lower. Experiment and watch the world around you.

[talats]

Thanks Janusz,
I am downloading it right now. I'll try and see what will happen.
Just in case, can I contact you in pvt if I have some quest on it?

Jure,
Unfortunately I don't have Maxwell and/or 3DS Max with Vray, so I am not able to compare nothing. And even if I had it, I wouldn't know where to go and check because I don't know how to use those programs.

Anyway, you are always in first line to help me, so thank you man.

Roberto

[talats]

Hey Jhony, just apply those nodes to one surface of my scene (on the floor) using my orinal textures. It seems that it slow down the render. Is it possibile or i miss something?

Roberto

[Janusz Biela]

Hey Jhony, just apply those nodes to one surface of my scene (on the floor) using my orinal textures. It seems that it slow down the render. Is it possibile or i miss something?

Roberto

maybe becouse of fresnel (high reflection on 90 degree.....)

[Janusz Biela]

Thanks Janusz,
I am downloading it right now. I'll try and see what will happen.
Just in case, can I contact you in pvt if I have some quest on it?

Jure,
Unfortunately I don't have Maxwell and/or 3DS Max with Vray, so I am not able to compare nothing. And even if I had it, I wouldn't know where to go and check because I don't know how to use those programs.

Anyway, you are always in first line to help me, so thank you man.

Roberto

My Skype: johny_quick

[bigstick]

Try these:-

http://www.robinwood.com/Catalog/Techni ... xList.html

http://interactagram.com/physics/optics/refraction/

http://www.pixelandpoly.com/ior.html