Hey David25, prepare for some rambling!
New Zoomify example at: http://www.mapformat...s/ressler3D.htm
More raster style samples at: http://www.mapformat...us/3Draster.htm
This type of cartography - 3D pictorial birds-eye-view map illustration - is more of an artistic form yet highly functional for navigational purposes. You need to have graphic design and illustration and even marketing skills so it is not easy to replicate this particular style as a lay-person. For instance, I've been developing my style for several years now - it has evolved, so it's not like I just plug in a certain Photoshop filter and voila my maps come out like this. This is my unique style whereas other 3D pictorial map illustrators have there unique style as well. Everyone's will be different. Plus, I have over 20 years in the design field as an art director/designer.
There is alot of time and patience involved in the hand drawing. But what I have done to make these illustrations more efficient from a profit standpoint is I've illustrated a library of trees from previous maps as well as grass textures and color schemes. That gives the particular Karpovage "raster" look to it. So, I pull from my previous maps instead of redrawing from scratch. This adds to the consistency clients expect.
I use Adobe Photoshop CS3. I purchased Adobe Creative Suite 3 which included PS as well as lots of other Adobe software I use like InDesign and Illustrator. This particular illustration was done as "layers" which makes life so much easier when drawing. Layers also allow masking and transparency and pixel selection much easier too. There are alot of keyboard shortcuts and filtering and other tips and tricks I've developed for my style as well which you will learn in time. I also work on a top of the line iMac with a wide cinema screen. These raster illustrations are huge in size and you need a computer that can handle it. Again, that is a time = profit investment. I used to sit there for 20 minutes while my file saved on the old computer. Now, I wait just minutes. I also use a Wacom tablet 11x17 and digital pen so I actually am drawing. The Wacom pen is like and airbrush that is sensitive to the touch and pressure. It's awesome!
For references, I prefer hi-res aerial images from multiple perspectives that either a client supplies or that we book with an aerial photographer. That is the best to work from. Other sources of reference are online but they may be outdated, obscured, are low resolution and of lesser quality. For this particular illustration I had none of the above other than a site plan and ground shots provided by the client Ressler Motors. The site plan was KEY to making this illustration happen. The grounds shots were essential as well because I had never even visited Montana. So, I needed a visual reference of what these buildings actually looked like. The ground shots were simply that - a reference that I kept referring back to.
Hope this helps. Feel free to contact me privately for more information too.