Hello my friend, I saw the images you have posted, and the difference and issue you are talking about. I faced these kinds of problems at first when I was learning materials in VRay.
Basically, these types of materials depend on the bitmaps for a lot of their realism, like the surface properties (bump, reflection glossiness, amount of reflection). When we try to import some material in the library of max, usually max looks up for the actual path of the bitmaps, place where the bitmap was originally stored, during the creation process. Since our PC does not have those special names of the directories, max can not find bitmaps, for example, I create a material and I have all of my bitmaps stored in C:\Users\SomeName\Documents\Textures, my max will register this path as the first priority to look for, even if I export my material as a .mat file. Now, when someone else downloads my material from internet, their PC will look for the path which has been assigned for the bitmaps previously, but it will not be able to find it. This will create a mess and the materials will not work as they should.
To solve this problem, the only way is to reload the bitmaps. You said you have problems loading regular .jpeg files, as you are still learning. It is very simple, you just open your material browser, in that, when you select your VRay Mtl, next to your diffuse color, there is a small box, click on that, it will ask what type of file you want to place, you click on Bitmap (can include .jpeg, .png, .psd and other image files), then search for the bitmap you want to use, in your case, the place where you might have downloaded your material, they would have provided the bitmaps with it. Search the desired bitmap and viola.
The moment you do this, you will see a "M" in place of that box, it means that channel is influenced by some kind of map (in our case, bitmap). Similar "M" will be there in reflect, reflect glossiness or any other area. Click on those "M" and in the new tab, you will find a source, pretty much similar to the "path" I have been talking about, look for the last "\" and the name after that, that name is the bitmap you are looking for (I hope I am not making you feel bad by so much explanation).
Apart from these small boxes, there is a "Maps" section in every Shader, be it VRay, Mental Ray or Standard Scanline. Those "Maps" are different channels which effect and control the properties of materials, you need to explore your downloaded material before you proceed with the application. Please find all the maps that are missing or those which your PC can not locate because of wrong path and replace them with whatever you feel like.
I hope my explanation comes in handy to you and to any other who might find this problem a headache. :)
Please feel free to drop by an e-mail if need arrives at : sam2maddy2001@gmail.com
or you can visit my facebook page : https://www.facebook.com/vraypage
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Happy Rendering!
Regards!
Tanay Pathak
