Are your eyes trained to detect when a scene from the new episode of Game of Thrones is ACTUAL footage, photo-real graphics, or a combination of both? (Spoiler alert, it’s almost always the last one!) Or is it the case that you couldn’t care less, as long as it looks real?
Either way, there’s no doubt that you can recognize when something just doesn’t look quite right.
Rendering photo-real images and scenes is one of the biggest challenges in our line of work. There are many factors that contribute to an image being fully believable, including perspective, texturing, and lighting. For most 3D animations, you’d set up some virtual light sources in your scene, and rely on a process called rasterization— but because this process doesn’t emulate the way light actually behaves, it’s very difficult to create something photo-realistic this way
Render engines use various methods to emulate the way actual light would behave through techniques like path tracing. Path tracing shoots “rays” into the scene, that then bounce around all the surfaces until they either reach a source of light, or decay over time. When done correctly, the result is pixels that are accurately lit and include details like reflections of color from surrounding objects.
Path tracing is straight up awesome, but even with a render farm (multiple machines all working together to speed up render times) it can take a very long time to calculate, so when working on longer animations, it isn’t always a workable solution. Lucky for us animators and CG experts, there is a ton of innovation going on right now around this technology.
For example, “real time path tracing” was just introduced, and although the engines we use for this technique don’t deliver quite the same level of detail (yet), what you see on your screen is exactly what your output is going to look like without any render time, which is a mind blowing advancement.
Another example is Nvidia’s newest line of graphics cards, branded “RTX”, which drastically cut down render times with engines like Arnold GPU or Octane. In my own testing of their new technology, I ran a single RTX 2080 against our 3 GTX 1080ti’s using the newest version of OctaneBench and the single RTX card managed to beat our multi-card setup.
True photo-realism is very difficult to achieve, but with new developments in hardware and software supporting path tracing, it’s never been more accessible.
We didn’t contribute VFX work to “The Wolf of Wall Street”, but we do enjoy this peek into the VFX/compositing process:
The Wolf of Wall Street VFX Highlights from Brainstorm Digital on Vimeo.