HOW DO YOU MAKE YOUR CGI RENDERS LOOK LIKE REAL PHOTOS?
"What's happened with computer technology is perfectly time for someone with my set of skills. I tell stories with pictures. What I love about CGI is that if I can think it, it can be put on the screen .” – Frank Miller
LEARNING 3D FOR THE FIRST TIME
This is a question I'm often asked as artists begin to venture into 3D software for the first time and are considering Cinema 4D as an option. The answer is definitely a bit more complicated than a simple yes or no response. Let's talk about it! In the video above, I discuss Cinema 4D's learning curve, how to lessen that curve and begin the journey. I talk about ways of learning, feedback, and the importance of community-based mentorship.
You'll also get to see parts of an interview with Ashley Murrel, a current student in the PRO EDU 6-Week CGI Course for photographers. This is an excellent opportunity to look at what's possible within just 4 weeks of using Cinema 4D.
UNDERSTANDING PHOTOGRAPHY HELPS LEARN CG
Having a solid background in or understanding of photography will dramatically aid in creating photorealistic 3D renders. Not only do photographers understand cameras, lighting techniques, and composition, but they know what flaws cameras naturally produce. This is vital as in CGI, creating flawless imagery is easy... adding those real-life imperfections is precisely the attention to detail needed to create realistic renders.
Lighting with intention is critical in creating real lighting scenarios. As a beginner, it's pretty easy to overcomplicate what should be a simple light setup. I remember aimlessly placing random lights into my scenes with arbitrary focal lengths, which lead to bland renders as there was no focal point in the image. This is where studying lighting, shadows, focal lengths, composition, and camera functionality come into play.
Going the extra mile to add film grain, chromatic aberration, and effects like bloom and glare will increase your renders' realism! We have loads of training here at PRO EDU that can aid in this journey!
USE GOOD REFERENCE TO ENSURE ACCURACY
Using good reference imagery on any project will increase your chances of realism by giving you a solid target to hit. Using Google images, Pinterest or other searching platforms is excellent. I personally like to build reference boards on Pinterest while planning a project and then pull pictures to place in PureRefwhen it's time to work.
PureRef is an excellent application for PC, Mac, and Linux that allows you to store multiple reference images on a single canvas while you work. I generally keep this open on a second monitor next to my render view.
HQ MODELS AND BEVELED EDGES
It should go without saying that using high-quality 3D models plays a crucial role in achieving photo-real renders. Though not every model has to be complicated, it should have enough detail to provide clean results when applying textures, materials, and lighting to your scene. One of the biggest mistakes I made early on was not adding bevels to the edges of my 3D models.
I would often leave a flat, solid 90-degree hard edge that would read as flat when lit. Adding small bevels to your models will significantly increase the level of realism as nearly every edge in the real world has some kind of bevel to it.
If you're using CAD models, consider using a "round edges" shader when creating materials. This is a great way to fake bevels without having to model them by hand! See our previous blog where I share the list of places I go first for resources!
TEXTURES AND MATERIALS
Finding quality textures these days isn't tough at all. The internet is filled with great paid and free assets to use. If you're going for photorealism, make sure to pay attention to the scale of your textures. Generally speaking, if your textures are larger than they would appear in real life, it's easy to spot that something is off.
On the contrary, making your textures too small can create a "repeat" or repetitive pattern across the surface of your model. This can be a dead giveaway that the scene is CGI. Finding this balance in quality and texture scale is where the excellent reference comes into play. As far as texture sizes are concerned, the closer to a model you are, the higher resolution you'll want your textures to be. If your model is further in the background, you can save your system resources by using smaller textures as the details won't be seen as clearly.
When working with materials, adding a breakup to your model's surface will go a long way toward achieving photorealism. We call these surface imperfections. This can often be as simple as adding a "roughness map" to add variation to the reflection levels on a material's surface.
Using roughness maps and textures in the bump or normal channels will help sell many effects like scratches or indents on the surface without dramatically hindering render time. This is one reason I like using PBR materials when possible. They give a great range of texture maps to start from building materials, and I can add complexity as needed. I generally like to start with the "diffuse" or color layer and add variation to each map as I build materials.
Understanding how to manipulate materials will give you control in creating subtle imperfections or heavy battle-worn effects on the fly. It's important to remember that not all materials have the same reflection values. Learning to break materials up by properties is a must in striving for realism.
POST PRODUCTION IN PHOTOSHOP
Post-production in CGI is just as important as with any other medium of digital imagery. Compositing 3D renders offers much more control than traditional photography, and render layers make them much easier to manipulate. On more simple renders or personal work, I like to keep the post-production process simple. It usually starts with using Camera Raw, just as I would with a photograph and building from there. I add bits of grain, chromatic aberration, and various lens effects to help sell renders as real.
CONCLUSION
Though this list is only a great starting point in creating photorealistic 3D renders, hopefully, it's a great starting point in your journey. There are many details to consider, and in the end, it comes down to gaining experience in creating such results.
Always remember to pack a good set of reference images when starting projects. Smartphones these days are a quick and easy way to get started. Starting with simple scenes and objects will significantly aid in the ability to move to larger-scale productions. One of my favorite parts of creating real photo CGI is the need to study my environment and really pay attention to the details around me.
