Gllass and scratched chrome ball shader?

[shunter]

Hello everyone;
I am in the process of trying to work on some shaders for my thesis project. I have created a pinball machine. Everything has gone well up to this point. I created a glass shader using different methods and ended up with a Mia_Material_X. I feel the glass is feeling realistic and I realize that glass has some bluriness, yet when you look through the top into the machine there are blurry areas where I feel it should not be blurry. For instance, over the typography at the top of the machine (see image). I realize I can increase the samples in render but I think that will really bog the machine down.

Also, I created a pinball. The ball was also created with a Mia Material X. Only problem is it needs some scratches which I attempted to create using a bump map. Doesn’t work. I was thinking of trying an anistropic material and using the recipe for brushed metal where I could possibly turn down some of the scratches and maybe increase specularity? I am also uploading an image that shows my progress thus far. I am thinking if I cannot get the scratches to work in Maya I may have to produce them in-post using Nuke.

Any suggestions would be very helpful Suzanne

[dcompz]

Hey Suzanne,

The glass is looking pretty good over all. It's been a while since I played with materials in Maya but I seem to recall having similar issues with the mia_material glass from time to time. I remember having to play with it a fair bit to get a result I really was happy with. You could try adjusting the glossiness on the refraction. Usually turning the glossiness down gives it more of an opaque 'frosted' look which might be part of the problem. More sampling would probably help too but as you said, it will slow things down. You could also maybe try some of the other glass presets or mixing a few of them.

As far as the scratches go, I would suggest making a scuff/scratch map for the reflectivity to create duller areas which is what a scratch would do on a chrome surface. Using a subtle bump or normal map could also help but it is unlikely a ball like that would have any deep scoring in it so I wouldn't recommend pushing it too hard. If you want the entire surface to look scuffed up, then playing with a mix of the chrome and anisotropic might work out too. If you are having trouble getting the bump maps to actually work, the bump map slot for mia_material is buggy in some versions of Maya and won't actually apply the bump if you link through there. The bump will still work but you will need to hook it up manually in the Hypershade.

If you are still having trouble with it, I would personally go the Nuke route and output a UV pass. That is just my personal preference as you have a ton of control and don't have to waste lots of extra time rendering revisions. You should be able to get pretty good results straight out of Maya though if you aren't comfortable with that.

Hope some of this will be useful. Good luck!

- Dan

[shunter]

Thank you so much Dan for your advice. I did get the glass to work. I had to set the shader blur to off and to Mitchell in the render settings. A friend of mine swapped files and I she did not have the blurry image problem under her glass.

I am still working on the chrome ball and have tried some variations to no avail. I will, however; try your suggestions Thanks again.