This post will outline the production pipeline for animation and 3D modeling, as part of my elective module for university. I will cover 9 different topics, from pre-production to compositing, and explain what they are and give examples of what they look like.
Starting off with pre-production, or as many also may call concepting. Concepting can be anything from collecting a set of reference images on pinterest, sketching something on a piece of paper, or taking a photo as a reference. It’s important to have visual aid with you every time you are about to sit down and model so that you can keep a consistent idea of what the final model is going to look like. These reference photos can be placed inside most 3D modeling programs to model after, which also allows you to get accurate measurements of what you are trying to create.
So when you have your reference photos all set up it’s time to start modeling. 3D modelling is essentially like modeling with clay (there are several products that act exactly like clay) but digitally and with polygons. For example, a cube is made out of 6 sides, and therefore has 6 polygons. A good way to think of them is sheets of hard paper that you stitch together into models. Where these polygons connect, there is always a vertex. These vertices are dots that when interacted with move all edges attached to it. Edges are essentially that, edges or lines. Below are some examples of this. The highlighted areas are the ones mentioned above.
Texturing & Shading
Texturing is the process of applying images or paint to a 3D object. It is a very complicated process that requires a few procedures, one of which being UV mapping. In order to paint on a 3D surface you need to flatten it out to a single 2D image. This is what UV mapping is. Once you have a UV map image you can hop into any drawing program that you like and start drawing on it. This is then brought back into the modeling program and applied to a model.
Shading (in 3D modeling terms), is telling your application what material the object is made out of, for example iron or brass. This is an alternative to texturing where the detail might be more in the model itself than on the texture. For example, for the robot model above, instead of using a painted red for the body, I could have used red metal shading, at the cost of the detail.
Rigging & Animation
If you want to make a model you have move and animate, you first have to start of with the rigging. Rigging is the concept of placing a skeleton inside your model, with control points that are then used to move the skeleton around so that you can animate it. Usually, the control points sit in all the joints of your model, so that you can rotate them as well as move them at the same time. Then you have to bind the model’s skin to the bones, so that it moves and bends naturally. This can be done using a method called Vertex painting, where you decide how much each bone influences each vertex by painting them in a “colour”. White represents 1, which is fully influenced, and black represents 0 which is no influence.
It’s time to make the character move. To do this we have to get used with the terms “frame” and “keyframe”. A frame is a part of a second and on each frame the position, rotation and scale can be recorded. If that happens, it becomes a keyframe. There are 24 frames in a second, and if you’ve recorded the position of an object all 24 frames of a second, the 3D program you are using will create an animation out of the keyframes.
Lighting in 3D animation is pretty straight forward. It is used to light up a scene in the final render. However, much like in any type of media, the lighting is used to set the mood in your scene. It might depend on the angle the light is coming from, how many lights you use in your scene, or what colour you are using for the light. There are also different types of light, and I will list the most common ones here. There are spotlights, that project light in a cone. There are Point lights or omni lights, that project lights in all directions originating from a specific point. There are directional lights, that most people tend to use as the sun. Directional lights light up the whole scene from a certain direction, still casting shadows. There is an alternative to this called skylight, which illuminates an entire scene but doesn’t cast shadows. It creates a sort of natural light. Finally, there is area light, which creates a softer light from an area. Sort of as if you were to have a light the size of a window and aimed it at an object.
Rendering is technically the final stage of 3D modelling, where everything in your scene is placed into a single image that the application, with assistance from your computer's settings, creates for you. It all boils down to the press of a button, but there is a lot of tweaks and settings you can use to either render more efficiently, or to alter the way it renders with the help of filters and so on. In an animation for example, rendering would take a very long time since a video is consisting of several images that each has to be rendered with the effects.
Wherever you go to watch 3D modelling work, you’re most likely to stumble upon renders. It is the best way to get light and other visual effects into an image that looks fantastic. Above this you can see a picture of a blacksmiths station. That image is the final render of a scene that has used many of the techniques that I’ve talked about above.
Compositing is combining visual elements together into one single media. For example, If I were to make an animation of a robot, and with the help of shading and lighting make it look realistic, and then finally place it in a video, that would be compositing. Using a green screen is a type of compositing, but also using photoshop to combine different elements.
There are different ways of doing this. Part of the compositing progress can be rendering the image in layers. For example, first doing a reflection render that only renders the shiny-ness of an object. Then on top of that doing a highlight pass for edges and a beauty pass for the textures itself. These can then be put together for a final image render that is also part of the composition process.
Birn, J. (2014). 3D Compositing at 3dRender.com. Retrieved from http://www.3drender.com/light/compositing/index.html
Hunt, A. (2015). Introduction to 3D. Retrieved from http://www.cgstudentawards.com/magazine/entry/introduction-to-3d
Slick, J. (2018). Get a Brief Overview of the Complex Process of Rendering. Retrieved from https://www.lifewire.com/what-is-rendering-1954