core skills

Rob Redman shows how making your CG camera emulate a real-world lens can add realism to every piece you render

Make your CG camera emulate a real-world lens in Cinema 4D

There was a time, not all that long ago, when it was easy to distinguish between work created in-camera and work that was computer-generated. There were a number of reasons for this, including the fact that technology hadn’t quite reached a point that enabled artists to present their visions as they would like, or that possibilities existed but were too time consuming.

Those reasons are the logistical, technology-based aspects, though. There is another, more fundamental factor that has now been overcome. It features in almost all good CG, including much of the stylised, nonphotorealistic work we see, both on screen and in print. That would be some good old dirt. What really sells a lot of the 3D work we see now is natural chaos: wear and tear, dust and dirt and all the other minute details that stop everything from looking too crisp and perfect.

Take this a step further, and you can start to produce remarkably realistic and believable art. Start to add those little distortions, dust and scratches to your CG lens. There are many things we can do to make our render lens feel more like its physical counterpart. Real lenses all have a certain amount of distortion and artefacting, which may or may not increase as light hits at certain angles, producing flares and colour shifting. Then there are the different shapes and blade counts of the iris itself, which all produce different kinds of out-of-focus blurs, highlights and glows (known as bokeh). To recreate these effects, most of the main 3D applications now have systems in place to control these effects – either as a post effect or during render time. For this example, I will use Maxon’s Cinema 4D and its physical renderer, as well as showing a third-party renderer’s solution: in this case, Maxwell from Next Limit.

Another factor to keep in mind is scale. Some renderers and their associated effects (in particular lighting) rely on a real-world scale to produce predictable and consistent results. So next time you’re modelling a photo studio and some objects to ‘photograph’, model them at their correct size, and you will find it much easier to light and render. For all the assets you need go to www. 3dworldmag.com/vault