Intermediate introduction?

[5parta]

Hi,
first time poster here so I hope this doesn't offend/annoy too many people.

So far, I've used mental ray only for adding GI/FG/SSS to my renders. Being comfortable enough with those, I'd like to extend my knowledge to mental ray shaders. Looking through the docs and online threads/tuts, I've managed to sorta get my head around basic stuff like dielectric and dgs, but barely.

Im having loads of trouble figuring out how to pipe basic color textures into the mr materials. Sometimes I've managed to get maya file nodes to work just fine, other times i get a "mayatomr.output file error". Trying to figure out why, I ended up reading about the custom globals>custom scene text, but I don't understand what it does or how to work with it, or how to get my head around whatever mentalrayTexture1 is and does.
Also, if I do something like create a mib_blinn, I really don't understand how it works beyond the attributes it holds. I uderstand that each mr node is design for one specific task, but I can't figure out, say, how to get the mib_blinn to have a spec highlight or reflections.

So what do you recommend I do here? This is really for personal projects and whatnot, my aim isn't to become some mr guru. I'd just like to take fuller advantage of what's available to me.

[Jak_Carver]

Well one example of piping a texture map into a DGS shader is to pipe the texture into your Diffuse channel. You can also texture shaders like mib_blinns and dielectric shaders the same way, but for dielectric pipe your texture map into the Color attribute, etc. I hope that helps, feel free to ask anything else.

[rygoody]

a couple of intermediate tips

Use the maya file node, the advantages offered by the mental ray native file nodes are pretty much nonexistant. You can get better results with eliptical filtering through the native mental ray file nodes, but quadratic filtering through the maya file node is not that far behind in visual quality and it is notably faster.

Use third party shaders. Things like mib_blinn and dgs are more examples of shaders than true production ready shaders. mia_material is all the rage now, ctrl_shading used to be all the rage, it's still good. Mental ray does ship with some production ready shaders though, the car paint phens and the miss_fast phens are examples of such things.

Always think in passes, get very comfortable with a compositing program. Unless you have a dedicated technical person to deal with keeping everything with mental ray running smoothly, then your gonna find mental ray is far too finnicky to rely on. So get in the habit of using mental ray for only what you need and nothing more, if you can do it in post in a compositing app, then do it that way. Try to do as much as possible in post.