When you get down to it, the concepts in CGI aren't all that different from those in photography. However, the tools and interfaces are quite different and the learning curve can be steep.|
Making CGI part of your toolset doesn't mean you have to learn how to do it yourself. There are many studios and individual artists that can work alongside a photographer just as retouchers do.
If you are looking to get your feet wet or at least want to understand the process, the path of least resistance is usually to download a trial version of a software package like Maya or 3ds Max, give yourself a couple of simple projects to complete and play around with the concepts. For those interested in a more formalized approach to learning the tools and the workflow, check out online classes, training sessions and other opportunities available from places like Gnomon, fxphd, Escape Studios and the 3D Training Institute.
CLASSES / TRAINING
The Gnomon School of Visual Effects offers online courses in a huge variety of areas related to CGI including design, illustration, sculpture, animation, lighting, compositing and overall digital workflows. They also offer DVDs and other learning materials through The Gnomon Workshop.
Escape Studios offers both mentored and self-directed online courses in all things CGI.
fxphd offers CGI training more attuned to those interested in vfx, post-production and animation fields.
The 3D Training Institute has online course offerings in a few of the major 3D applications such as Maya and 3ds Max that are more suited toward people looking to work in design and architecture fields.
Lynda.com offers a huge number of tutorials specific to different pieces of software, from Photoshop to Maya and Nuke.
ONLINE COMMUNITIES / NEWS / TUTORIALS
cgsociety.org is one of the most active online communities for CG artists and professionals.
creativecrash.com (formerly Highend3d.com) is a great online community that offers a lot of great learning resources on many topics and application.
ACM SIGGRAPH's Learning Resources on the Web directory has an exhaustive list of stuff.
Autodesk AREA offers a lot of tutorials and information for produced by Autodesk (such as Maya, 3ds Max, Mudbox, Combustion, etc).
VFXWorld posts articles and lot of other good information about CGI, mostly from the world of visual effects.
3D World offers up articles, tool reviews, tutorials and a forum for discussing the world of CGI.
STOCK MODELS, TEXTURES AND HDRI
TurboSquid is one of the biggest and most respected stock model companies, offering over 250,000 models for purchase.
PK3D.com offers stock models and HDRI panos.
Humster3D offers a large selection of stock models for cars, vehicles, electronics and more.
The 3D Studio is another stock model company that offers everything from aircraft, to animals, to buildings, people and just about everything in between.
Exhange3D.com has a variety of stock models and textures available for purchase.
3docean offers inexpensive 3D models, textures, materials and shaders.
cgtrader makes available free and paid stock 3D models in a variety of categories.
TextureKing has a huge number of royalty-free stock textures for 3D projects.
ImageARC is another royalty-free stock texture company offering up more than 60,000 textures for use in 2D and 3D projects.
CG Textures is purported to be the world's largest archive of free texture maps.
Archibase has a whole page with links for 3D models and textures.
HDR Labs sIBL archive offers up a large assortment of free HDRI for use in Image Based Lighting (IBL) applications. When used with applications like Maya, 3ds Max, Softimage, C4D, Lightwave and Modo, their proprietary IBL format requires use of plugins which are freely available on their website.
HDRI-Hub provides a variety of royalty-free, high resolution HDRI panos and textures.
HDRelements has an impressive library of HDR captures of light fixtures which can be used as emission maps for CG lights to more accurately represent real-world illumination sources.
AutoCAD has long been the industry standard for CAD.
Vectorworks is another great piece of CAD software that comes in several "flavors" that are tailored to specific industries and tasks.
General 3D/animation packages
Maya is still considered to be the industry standard for 3D animation.
3ds Max came from a background that was strongly integrated with AutoCAD, thus making it a one-time favorite of architects and designers. Now also used heavily in visual effects for television.
Softimage has been a long-time rival of Maya.
Houdini provides a more "procedural" and technical approach to 3D animation and is a favorite among those simulating natural phenomena such as smoke, water, fire and destruction (although it's good for much more than that).
Cinema 4D is a newer product in the 3D scene which is a favorite among motion graphic artists and is starting to find its way into more photo-real applications including visual effects.
Lightwave 3D has long been used in the production of visual effects for television and commercials.
Modo from Luxology is a modeling, animation and rendering tool built with designers in mind. Many outside of that niche use it for modeling due to it's strong toolset in that area.
KeyShot is a newer 3D package geared specifically toward product imagery.
Z-Brush was one of the first modeling applications to provide a workflow that's much more like working with actual clay in the real world. Where older approaches saw models created by arranging polygons by hand, Z-Brush models are "sculpted" out of basic shapes. Z-Brush also provides some strong 3D texturing tools.
Mudbox provides a workflow similar to that of Z-Brush where models are "sculpted." Mudbox also contains a robust set of 3D texturing tools.
Rhino is a modeling tool often used by designers.
BodyPaint is a great all-around 3D texturing package that integrates well with Photoshop.
Photoshop is still an application central to CGI for 2D texture and matte painting.
Photo Modeler is a commercially-available software package for photogrammetry.
ImageModeler, now bundled with many Autodesk 3D products, was inspired by Paul Debevec's photogrammetry research in the mid 1990s.
Autodesk's Project Photofly provides a way for users to generate 3D models entirely from photographs for free using cloud computing.
Enwaii is an up-and-coming complete photogrammetry pipeline geared toward visual effects.
V-Ray is a favorite for architectural visualization and other applications where high levels of realism are important. More and more, it's also being used in the production and visual effects and 3d animation. V-Ray's claim to fame is that it can render highly realistic images in a fraction of the time it takes many other rendering engines to do so.
Arnold is quickly being embraced by many visual effects and animation studios as a renderer which can generate very realistic images quickly and without a lot of technical controls unintuitive to artists. Arnold was the renderer of choice for the majority of the world on 2013's Gravity
Mental Ray is one of the industry standard rendering engines that provides a lot of features like global illumination and image-based lighting that allow it to create images with incredible realism.
Maxwell is another physics-based rendering engine that can provide high levels of realism. It's available for 3ds Max, Maya, Lightwave, Rhino and Cinema 4D.
Renderman, developed by PIXAR, is the industry standard for visual effects production and is used by vfx shops like ILM, Digital Domain and Sony Pictures Imageworks.
Brazil is a rendering engine similar to V-Ray that provides high levels of realism.
Nuke was originally developed by Digital Domain for use in-house and then became a commercially-available product. It's now become the industry standard for most visual effects studios.
After Effects is a favorite among those production motion graphics and visual effects on a budget.
Photoshop is a perfect compositing and paint package for still images.
Flame and Inferno are what are known as a high-speed compositing systems, capable of doing operations in a fraction of the time it would take in something like Nuke or Shake.
Fusion is another compositing package being used by a number of visual effects and animation studios.