I'm not a great artist. I did some drawing classes a few years ago which I quite enjoyed, but I didn't produce too many masterpieces -- although I liked this one:
I am decent with a camera -- I was working the macro lens a couple weekends ago shooting some kitchen items to try as textures. Sugar looks like diamonds, and icing sugar looks like weird rock formations. Shortly afterwards I found cgtextures.com
which is an amazing resource for textures.
You may be able to tell, I've been having a whole lot of fun the last few weeks. As a programmer I was surprised at how wonderful and satisfying it is to put art into a game engine. It's not something I really got to do working on game engines at EA. With the new art in place, a couple weeks ago I took the first screenshot where I excitedly thought "I could show this to people and they wouldn't laugh!"
When I started this project, my plan for the art had some vagaries -- mainly due to my almost complete inexperience in the area. I did have the good sense to pick a game genre that has modest art requirements. Despite all advice to the contrary, I decided to make a 3D game because I knew there was no way I could build good 2D art, but there was at least a chance I could build 3D art. (And I figured I could buy a lot of the 3D buildings, vehicles and miscellaneous props I would need from online art sites.) I was confident I could create good-looking outdoor environments with a bit of procedural technology and some skillful camera work (which has turned out quite nicely.) I also decided early on to save myself a whole lot of pain: there are no humanoids in the game. People require a skeletal animation system and motion capture (or lots of hand animation) to get them moving. If you want to get close to them they need clothes, faces, skin -- things that are difficult to render and require a lot of art effort.
When I got stuck, I figured I'd hire a real artist to help me out.
I've been learning a lot about building art for games. When I started, I never would have imagined I'd be adjusting the individual color channels of textures so they all have the same general color temperature (and be prettier.) Gimp is turning out to be a great tool for image work. I found this normal map plugin which occasionally produces normal maps I can use (although sometimes it doesn't -- making normal maps from photos is pretty sketchy at the best of times.) Normal maps make everything so much prettier!
I've also been doing some modelling in Blender 3D. It still amazes me that every time I open that program I have to look up how to work it. That said, there are a lot of tutorial videos on the web which are usually pretty easy to follow. I used this one this morning to help me build a boulder prop. Imagine my annoyance when I got to the end of the video, quite happy with the nice rock mesh I'd built, and the guy recording it said, "oh, I totally forgot something important, let me show you how this is supposed to work out" and loaded up a finished rock model, leaving me with a nice, but completely untextured rock with no way to texture it. Fortunately, the method he showed only takes about three minutes. I figured out how to do UV unwrapping later and got it nicely textured. Then I removed the specular from the rock's material because the rock was too shiny. Now I want a normal map to make it bumpy. Art is a process.
I added randomly placed static props to the world last week so that one rock has become hundreds of rock formations throughout the world. My terrain builder uses a set of rules to place it in the world at different heights above the terrain, then rotates it, with the result that every rock formation looks unique.
One word of warning: Look carefully at the models you buy online. In one set of models I bought I found a phone booth model that had a penis and testicles painted on the side. I don't think I'll be using that one.
An artist friend told me "You'll get one thing looking good, and it'll make something else look bad, then you'll make that look better, then something else will look bad. You'll go on like that until you have to ship it." That advice has turned out to be amusingly prescient.