Let's say you are a Photoshop pro. Odds are that you'll recognize the Photoshop icon anywhere, regardless of any media located behind it. I recognize Explorer, Photoshop, AIM, Word, Excel and so on, without the aid of any sample media in the icon.
If you are a newbie, you probably won't just walk up to a computer and need to find a imaging program like Photoshop. If you are a newbie and you install Photoshop or Excel, you can locate the application in the Applications Folder, where the icon will be accompanied by the word "Photoshop" or "Excel." Once you've launched the application, there is a great chance you will recognize the icon from its appearance in the dock from that moment on. The whole point of icons is that they are easy to memorize and recognize. A great icon needs very little help and doesn't require a Genre to associate it with a function.
To give Apple some credit, I believe that the Genre concept is an excellent idea in theory, just not in practice. In the real-world, outside of Apple and Apple's applications, it doesn't really work that well. I suggest that you do your best to locate a happy medium between following the genre guidelines and satisfying your personal preferences and needs. If you can't fit your icon/brand into the guidelines or you want to express only your brand, then ignore them. After all, they are guidelines, not laws of physics.
The fact is, the better your icon looks and the more unique it is in reflecting your brand, the more effective it will be, regardless of its Genre.
Amityville Horror, Jaws, application icons: All in 3D!
When working with photorealism, specifically 3D, there are a number of issues to consider. First of all you need an application that can not only create 3D modeling, but can also handle rendering (turning 3D models and textures into images). These programs use calculations to calculate light, space, and texture. Those mathematical calculations are developed by super-human government experiments who need a special apparatus to keep their enormous brains from tipping their heads over. Me, I just use a neck brace.
For my 3D work, I use Strata's, Strata 3D. What I like about the application is that you get all the 3D tools you need and an excellent rendering engine for a mere pittance of about $150. Why do I use a 3D application versus an illustration app? With a 3D program, I have a lot more control over every aspect of space, effects, and light.
For your icons, you can build your own models or you can purchase models that are already built and textured. This can save you a lot of development time. One example of a company that builds models is Zygote. If you want to take an existing image and give it new life in 3D, Adobe's Streamline app allows you to take any image and convert it to geometry. Then you can pull it into 3D and do practically anything with it. I highly recommend this application!
When working with 3D in relation to Aqua icons, regardless of the application you use, you have to consider a few issues: detail, scaling, camera angles, and lighting.
In a previous column, I showed how an icon with a busy texture or pattern will have great difficulty retaining that pattern when scaled down. I also pointed out that busy images don't really look good at any size. One of the hardest lessons to learn (much like when drinking Guinness) is knowing when to say when.
I am of the school of thought that less is always more. In 3D, detail is even more nefarious when images get small. Some details will disappear, while others bleed into noise. There is one exception to this simplicity rule. If the detail that is lost in scaling down doesn't change the meaning of the icon or distract from the image as a whole, then it is okay.
One of the more crucial aspects when working with 3D and photorealism in icons is scaling. When you develop an icon at 128 x 128 pixels, it is easy to think, "Wow, I've got all this room to work in." That's where you'll get hammered. Most users will never see your icon at its largest size. However, you can render your images at any size you like when working on them. I recommend a size larger than 128 x 128 pixels. This gives you room to do additional detail work on the image in other programs like Photoshop, without any loss of data.
Mistakes are harder to correct at smaller sizes and I prefer to work with plenty of space and then scale down. When working with a 3D model and certain textures, I also find it easier to work with an object that has a bit of scale to it so I can see what I am doing.
Don't concern yourself too much with how large the object is in this relative space. It doesn't have to be built to scale, since you can render the final image to any size. If you are new to 3D as a guideline, you could insert a simple rectangular box to represent the "desktop" on which your icon will be placed -- you'll see this "desk" metaphor later). This will help give you some reference for which camera angles and directional lighting to use.
One warning when working with any icon: It is my opinion that using any form of text as your icon is a bad idea. Text does a terrible job of translating across the system, especially in 3D. Once scaling down comes into the equation, all meaning is lost.