Top Five Tips for Photorealism
Any artist would tell you that achieving photorealism can be quite a tricky feat when you first start creating renderings. There are several considerations one will need to make to achieve that satisfactory level of photorealism - so many, in fact, that not even a Top Five list of tips can really flesh out everything that needs acknowledged. With that said, here are my top five biggest tips that has helped me learn to create consistently photorealistic renders.
1. Post Processing and Color Correction
A common mistake that newer artists make is neglecting the power of post processing and compositing. Many artists consider their raw images as a complete "final" without fully realizing its potential in the hands of a program like Photoshop or even their renderer's frame buffer. It's entirely possible for a raw image to look amazing without bringing it into post, but doing so ultimately holds back the image's true capabilities.
Many renderers offer built-in post processing features in their frame buffer, allowing for some quick color corrections to help images look more natural and "pop," and artists who brings their renders a step further using programs such as Photoshop can truly bring out the hidden details and realism of their images.
2. Ignoring Little Details
A common mistake that most artists make is neglecting little details in their materials, models, and even lighting. Experts in the craft are constantly informing other artists that valuing details - should time permit - can ultimately make for a more realistic rendering. If you're an artist, you're probably tired of hearing about using surface imperfections, but allow me to drill it into your head once more and emphasize that they do make a significant difference in your renderings, especially in detail shots.
Other practices artists should adopt to add more detail into their rendering is to use IES light files (which are normally provided by manufacturers of lighting specs, should a specific model be called out by the designer), and chamfering their edges. Again, if you're an artist, you're probably tired of being told to chamfer the edges of your model, but allow me to further emphasize that it does make a difference in the quality of your renders.
3. Understand basic lighting fundamentals
Lighting is tricky. With the wrong mindset, many artists may create lighting that is either too blown out or too dark for clients and designers to be able to properly evaluate your renders. In extreme cases, artists may try to cheat the process of lighting and emit light from non-existent light sources, which ultimately brings down the quality of your renders.
If you're an artist, and lighting isn't your strong suit, return to fundamentals - ask yourself where light should be coming from and how much light should be emitting. Is there light coming in from the exterior environment - the sun, the moon? What are the interior light sources? How bright or warm should they be? Asking yourself these questions will ultimately make lighting your scene that much easier, especially if you're working with a renderer with a decent global illumination algorithm.
4. Use proper scale with materials
Another common mistake that many artists make is not properly scaling their materials in their scene. It happens very often - an artist downloads an awesome looking PBR material, plug in all of the images into their appropriate nodes, create a UVW map, hit "render," and scale of the material looks too big (or too small, in some cases). Many artists make the mistake of eyeballing their materials in the viewport, and basing whether the scale of their UVWs is correct based on intuition. That is not good practice.
Poliigon, Quixel, and even Substance have all made immense efforts in ensuring that for each of their materials, the scale of them is noted in the materials' information sheet. Even finish manufacturers such as Carnegie Fabrics have started including information regarding the unit scale of their fabrics in their rendering textures downloads. While it's generally encouraged to trust intuition when it comes to art, doing so in a situation when it comes to scaling material UVWs is largely discourage and unnecessary.
5. Proper Camera Compositing
A commonly overlooked issue when it comes to the architectural visualization industry is proper camera compositing. Working in this field, you'll have designers and clients look for specific views for you to use in a render to capture certain design elements in the context of the space. This is never a bad thing, as client/designer engagement is highly encouraged, but at times, this may lead to improper camera compositing.
The Rule of Thirds is a commonly utilized compositing guideline that places your subject in the left or right third of an image, leaving the other two thirds more open. Doing so makes your view both more interesting, and at times more realistic, especially if your camera settings are not set to traditional standards. If you're working on a project, and the render looks too "boring," and you've dialed in on every detail, it may be the camera angle.