Thought I'd try to save some time by providing answers to some of the most commonly asked questions here.
Q. The .zip file I downloaded is corrupt.
A. There's a problem with .zip files here at the site & Internet Explorer. If you use any other browser besides IE, like FireFox, etc., the .zip files here will download properly.
NOTE: Until this issue is tracked down & resolved you may want to use .rar instead of .zip when uploading content to the site.
Q. I've downloaded a file from the site here and it gives me a missing DLL or "Error loading ParamBlock2", or similar error when I load it...why?
A. You've downloaded a material that was made with a newer version of 3ds Max than what you're using. The most common example: You may have downloaded a 3ds Max 2009 material and tried to use that in 3ds Max 9.
NOTE (1): 3ds Max 9 is NOT the same as 3ds Max 2009! For further clarity, here's a roadmap of recent versions:
3ds Max 6 (rel.2003), 3ds Max 7 (rel.2004), 3ds Max 8 (rel.2005), 3ds Max 9 (rel.2006), 3ds Max 2008 (rel.2007), 3ds Max 2009 (rel.2008), 3ds Max 2010 (rel.2009).
NOTE (2): When submitting a file here on the site please use the "File Version" option to enter what version of 3ds Max the file was created with instead of something like "Ver. 1.0". Doing so will help users determine if the uploaded content will be compatable with their particular version of 3ds Max they are using.
Q. How do I use a .mat file?
A. Start 3ds Max. Open the material editor. Load the .mat file from the material editor ("Get Material" button). Apply the material to the objects in your scene. Render.
Naturally that's a condensed version. There are other things to consider like making certain you've configured your user paths/bitmaps properly. For more details also see these links in addition to the 3ds Max help file:
Q. I've downloaded/extracted a file from the site here and I don't see a .mat file or it has a Microsoft Office Access Table Shortcut file included...WTH?
A. It's there, but you either have the windows option "Hide known extensions" enabled or you have Microsoft Office installed and it's associated itself with .mat files. Either way it doesn't really matter, the 3ds Max material editor will still open/use the file regardless if the extension is hidden or associated with Microsoft Office.
Q. I have downloaded a material from the site here and when I open it with the material editor but it doesn't show up?
A. Are you certain that you've set mental ray as your renderer and not the default Scanline renderer? If you don't know how to change between the Scanline & mental ray renderers, then it's time to spend some "quality time" with the manual/help file before jumping in & using custom materials.
Q. Why is it that when I render the matlab scene the ground plane is almost black, or doesn't match the other samples posted here.
A. Gamma. There's a document included with the matlab that explains why I used certain gamma settings on the matlabs. In a nutshell if the ground plane is rendering very dark, you'll need to modify the utility gamma/gain shader that's applied to the base objects in the scene to suit your gamma settings. To do this you'll first need to unfreeze the objects (via object properties) then load those objects materials into the material editor and then set the gamma on the utility gamma/gain shader to 1.0 instead of 2.2. Alternatively you could leave the scene as is and simply set your bitmap input gamma to 1.0 when working with the matlab.
NOTE: At some point we'll revamp the matlabs and at that time readdress the gamma configuration since the DBR gamma issue I outline in the .pdf gamma document has been fixed in 3ds Max 2010.