how do i make a decent glass shader

[karldavies]

HI,

 

I am using maya and am struggling with a decent glass shader.

 

Its going to be used for the windows on the house i am making.

 

I have a sphere with a sky texture mapped to it which is visible in reflections and refractions.

 

I have a phong shader applied with reflectivity turned up high and transparency turned right up. So the curtains can be seen through

 

To be honest the settings make the render look rubbish, and I have no idea what i need to do.

 

Any help is much appreciated!!

 

thanks

[shaneis]

You could try the mia_material if you have Maya 8.5 (hit the preset button and choose "glass_pane"), or otherwise make a dielectric material and adjust it as you see fit. Each of which have the correct IoR - 1.5(ish). If you're getting blacks with the dielectric, tick the checkbox "ignore normals" and you're away. NOTE: if you are using G.I., you'll have to create another node - "dielectric_material_photon" from the "Photonic Materials" menu. Simply middle click and drag it onto the original dielectric material's "shader group" node (dielectric_material1SG) and choose "default" as the connection option. That way ensures that photns will react properly with the material. Similarly, if you are using the mia_material, you'll have to connect the photnic attributes - again, middle click and drag the material node onto the material's shading group node and select "default". Now the material is connected for photons and shadows.

 

Another note, hit this site

 

http://mentalraytips.blogspot.com/

 

Zap's kind of up with things for the MR4M shaders...considering he writes for them!

 

All the best,

 

Shane

[karldavies]

hi, i used the mia_material with the glass pane setting.

 

However its just coming out transparent. with no reflections.

 

Also i cant seem to get the sky i have mapped to a sphere to render in the reflections...

 

What do i need to do so i can get some nice clouds appearing in the window.

 

Thanks

[shaneis]

Check the RenderStats for the sphere - in it's attribute editor. Make sure that reflections are on. Secondly, make sure your raytracing settings are up high enough to allow the rays to make enough bounces. A good rule of thumb for glass in maya is to use reflection/ refraction =6, trace depth =12, and you can start with shadows = 2. All in your RenderSetings. Make sure each raytracing light has it's shadow rays equal to your renderSettings shadows (in this case, 2). You should also check that the sphere's normals are facing the rightway, for an envSphere, they should all be pointing inwards. If not, in polys menus, Normals>Reverse.

 

Give that a blast and post your results. Much easier to spot render problems with an image.