Hello, and welcome to Knowledge City's course on Advanced Blender 3D. My name is Jay, and today we will be learning about Blender's two primary render engines, which are used to produce photorealistic images. The first is the EV render engine, and the second is the cycles render engine. But first, let's understand what rendering actually is. Is the computer's process of calculating all the information in a scene, and combining the information into an image. This information includes, but is not limited to, the scene's lighting and the object textures, positions, reflections, amount of geometry, and overall complexity in the scene. Let's take a closer look. For starters, EV and cycles are only viewable when we are using the rendered method of display in our viewport. And we can get there by clicking on this button at the top right of our viewport. Next, let's enter our render properties by clicking on this icon here at the right. And we see the first method of rendering is called EV. Directly under that is where we can control our sampling. Sampling is basically the number of calculated passes Blender will use when rendering the scene. The lower the number, the less detail, and the higher the number, the more detail. And we have two sampling options. Render is in reference to the samples used when Blender processes a final rendering of our scene. And viewport is in reference to the samples used when Blender displays our scene here in our viewport. You'll notice I have more samplings assigned to my rendering compared to my viewport. This is because I am more concerned with the high quality of my final image than what I'm seeing in a working 3D environment. I've created this very basic scene comprised of five 3D objects resting on a backdrop with a camera and one area light. The window on the right is how the scene looks in our 3D viewport. And the image on the left is the final rendering of the scene. So what exactly is EV? EV is a real-time rendering engine. This means that everything we see in our 3D viewport or camera is being displayed immediately with very few calculations involved. This ability to view things in real-time allows us to work in Blender a lot faster because there is less stress on the computer and less information required to be displayed on our computer screen. The final render on the left looks pretty good. However, you'll notice that it's not realistic. The shadows don't conform to their respective objects. The reflections lack details of their surrounding objects. You can even see the shadow is almost separated from the pink object making the object look like it is floating. Overall, there is not enough detail to be a convincing photorealistic image. This is all because EV is meant to speed up our workflow without needing to put stress on our computer. This is also evident when we see that it took Blender only 6.5 seconds to render this entire scene. So EV is perfect when working in Blender before going to the next render engine, which is cycles. Let's switch from EV to cycles using the same scene. The first thing we notice is the amount of detail that begins to appear in our scene, and it's already starting to look photorealistic. This is because the cycles render engine uses what is called ray tracing, a method used to simulate the behavior of light in a real world. In a real world, light starts at its point of origin, for example, a light bulb in a room. The light travels from the bulb and it hits the items in the room, but the light doesn't stop traveling there. Based upon the properties of the items in the room, their color, texture, smoothness, and location, the light will bounce in different directions and ultimately illuminate the entire room. This is exactly what ray tracing does. It simulates the behavior of real world light by taking the rays of light that are emitted from the light source, analyzing the rays as a hidden object, calculating the trajectory of the rays based upon the material of that object, and displaying the final image on our screen. There's a couple things to consider, however, when working with cycles. First, it's extremely burdensome on the computer and may drastically slow it down. The second thing to consider is that cycles does not render in real time the way EV does. Notice the large blocks that appear when I orbit around my scene holding down my middle mouse button. This is because the rendering calculations haven't begun. However, when I let go of the middle mouse button, the image starts to appear, indicating the rendering has begun. A very commonly asked question is which render engine is better, EV or cycles? It's important to keep in mind that one is not better than the other. Instead, it's a matter of determining which one to use and when to use it. A good rule to follow is to use EV when you are working on your scene, such as modeling, animating, and texturing, basically when you need more speed than detail. Cycles, on the other hand, should be used once your entire scene is done and ready for rendering. Basically, when you can step away from your computer and let it do its processing. But of course, render times for both EV and cycles depend heavily upon your computer and its computing power. And these are Blender's two primary render engines, EV and Cycles, which are used to produce photorealistic images. Thank you very much for watching.