Are the remaining 20% custom materials not in the protein material catalog?

I've just come looking for help on exactly this subject as well because I've started to play around with 3dsMD 2012.

Some custom materials come across but not all using fbx.

I've been on a 3 day 3dsMax training course in the past but it still takes me a while to remember the workflow after importing a Revit fbx (at least it is a bit easier now that there is 3dsMax Design which is by default set up a little better for building related work).

The inclusion of the iRay rendering engine as an alternative to Mental Ray is intriguing.
It seems to offer 'idiot resistant' photo-realistic rendering... but you have to find how to turn it on first

After many years of using Cinema 4D to render Allplan exported models the Revit -> 3dsMax connection has been very hard work, although potentially the results can be a bit better.

Until someone comes up with a Revit 2012 version there is some help in this Revit Clinic blog post for Revit 2011:

FWIW I've just had a further play with taking an fbx out of Revit 2012 into 3ds Max Design 2012 and the materials are now there as they appear in a render of the View (using iRay which looks really good and fast) even though I can't make them appear in the actual viewport.

I don't know if it helped but I added my Revit custom textures folder to the Customize->Configure User Paths->External Files tab.

This may no longer be relevant but the first thing I always do when importing an fbx is delete the daylight system which comes in from Revit - you can select the big compass rose thing and delete that.
Then in 3dsMD use Lighting Analysis->Create->Daylight System - click OK to the offered 3dsMD setups...
click and drag in the viewport to create the compass rose and then click and drag to set the height of the 'sun' (I don't think height actually matters).

That will give much better daylight rendering results.

Hmm, this is strange, on some exports I can get the materials to appear in the Viewport but not in others - and sometimes the materials appear in the Viewport but don't render

Ian, you can right click on the text in the top left of the active view in 3dsMD which will bring up a menu, and then choose such as Materials->Shaded Materials with Maps or other related option to control what is displayed within the viewport.

iRay (F10 Common tab->Assign Renderer) is very fast at showing what you will get but leaves a lot of little white speckles on renderings for me, so far.
You can leave it running indefinitely and just choose when to exit or set it to specific time periods or number of passes.

To obtain a similar render using Mental Ray you need to enable Global Illumination in the same dialog once you set the renderer to MR (which it is by default I think) - it's under the Indirect Illumination tab.

You also need to enable an Exposure Control if it hasn't been automatically enabled already - Rendering->Environment & Effects->mr Photographic Exposure Control
I usually just take one of the presets offered to start with.
You can tweak the value to brighten up the scene if necessary.
If you created the 3dsMD daylight system mentioned earlier you can select it and using the Modify tab (icon with bent blue tube, near top right of screen) you can change the Location and time of year etc etc.

It's slowly coming back to me

Just rambling on...

Ah, I see - it's the materials - they work when rendered in Mental Ray in 3dsMD but not always in iRay.

Also, in the case of the materials not showing up in the viewports in 3ds max, Make sure that the "show material in viewport" button is activated.
In some cases when the scene is overexposed, or in other words the illumination too intense as is in the case of lighting with the sun or some bright light source, you will find that all materials come out the same color. In this case you can right click on the name of the view ( in the top left corner of the viewport) > go to lighting and change the lighting from "illuminate scene lights" to "illuminate with Default lights" this usually fixes the materials showing correctly in the viewport.
Hope this helps

For people using Revit>3ds Max> Vray.

Make sure you chose the link manager to import the fbx file, then chose to group the incoming geometry by materials. (This will make changing materials in the model a breeze.) then in the material editor window, you can click on the eyedropper tool and then click on the element in the model to acquire its material. Modify this material and it will change on all geometry that has the same material.

Thanks - coming from Cinema 4d I could never understand why you had to click that 'show material in viewport' button to get it to display in 3dsMax - but that's just one of those things I guess

The materials editor in 3dsMax I always found strange but the Slate Materials Editor is mind-boggling - looks fantastic - like one of those early Moog synthesizers where you used patch cords to connect filters and oscillators

/edit:
Just seen your second reply.

Many thanks, that's a great tip.

Now all I have to do is find the Link Manager

(The online Help is so slow - I guess there is a way to make it local just like in Revit 2012).

With the slate material editor I had some problems getting used to it, but once you get the hang of it, it allows for a great deal of control for the materials and also it allows you to understand better all the parameters and nested sub-materials that make up the main one. Although for more simple materials i just use the compact one.