View Layers Explained to the Simple Minded, Like Myself

Question

Although I've been learning Blender for six months I've only just come across the idea of View Layers and rendering separate layers.

You know how it goes; you want to learn 3D so you attack the jugular of the things that drew you to it in the first place - modelling, adding materials, animating etc. In the course of learning those, you pick up some other bits and pieces almost as a coincidence, while you miss others completely.

Can someone PLEASE point me in the direction of some tutorials that will explain View Layers (why we'd use them, how we use them etc). I've looked at a few already but all I've seen so far assume I know things that I don't, so I need some lessons that will spell things out to me as if I have a learning difficulty (which I may well have).

Many thanks, Mark

Answer 1

ok, i try:

View layer separate the objects of your scene.

E.g. if you have a torus and a cube in your scene.

You could add the torus to one view layer and the cube to another view layer.

The main reason for view layers (AFAIK) is compositing.

So you can e.g. give the view layer with the torus a glare node and you could give the view layer with the cube a pixelate filter.

In compositing you can combine these two layers to one picture (or animation).

The other reason for view layers are render times.

Maybe you have to render a scene for a customer. And customers often want changes. So the advantage of view layers are: you have already e.g. rendered the time expensive fog and he only wants to change the color of the car. By view layers + compositing you only have to render the car again and you can deliver your animation in time. If you would have to render the whole animation again it might take days....weeks....or longer ;) So basically view layer "split" the render process in different parts which you can then combine in the compositor.

Answer 2

View Layers allow you to easily save and switch between some visibility settings, for example in ViewLayer1 you can hide Collection1 and 2, while in ViewLayer2 these collections will be visible but some others will be hidden. This way you can test different solutions for your render (like enable or disable a set of lights for example). You can also enable or disable some settings in the View Layer panel.

But I guess View Layers are mainly used to combine different layers in the Compositor. In the Compositor you can assign an effect to some view layers but not to other ones (and therefore to some collections but not to other ones), then combine these view layers to have a unique render image. For example this way you can affect a Glare effect to some objects but not to other ones.

Answer 3

Even tho the post is a bit older and there have been awesome replies, allow me to explain the structure a little more:

When you have objects in your Blender file they belong to a certain Scene. Having multiple scenes is like using multiple project files, with the exception, that Scenes are able to interact with each other. You might have seen the word "Scene Collection" in your Outliner, which notes, that the subordinate collections are part of the currently selected Scene data block.

View Layers, formerly Render Layers are a kind of subdivision for a Scene. While the "Render", "World" and "Scene" properties are the same for the entire Scene no matter the view layer, the properties for Collections and View Layers can vary per layer. Therefore additional layers are useful to split up the render process into what is rendered and which passes you can obtain. To combine them later you can use the compositor or export them to use in another software.

The render settings are still given by the Scene and also the Camera is the same for each layer. The mere purpose of extra layers is to split up your render into multiple components to process individually (and often combine again later). A basic example would be separating your Mist and Fog elements (not to get confused with the Mist pass) from your objects, to later add then back in. While it is possible to do alot of these color correction and compositing tweaks beforehand in the shaders, view layers allow tweaking an entire group of things and are especially useful for animation to allow post processing for all the frames and their passes with the given Compositing Node Tree rather than having to edit them together manually later.

However if you want to render multiple parts of a project in the same step, without leaving your single file and going through annoying import and export steps, using multiple Scenes can be extreme powerful. Each of your Scenes has their own Collections, Worlds, Render settings and even Output settings. Also the view layers are unique to each Scene. This can handy when switching between two environments during an animation.

Imagine your character looks through a portal into a totally different dimension, using Scenes makes this transition possible for compositing without additional editing afterwards. While it is possible to get a transition like this with shaders, it offers a sort of isolation from the other environments so you can work on each individually and aren't as prone to issues.

What I recently used two Scenes for is rendering parts of an image as Orthographic while the other used Perspective. Instead of going through the export process and managing two Blender files multiple times for each change. The setup allowed me to make changes and not worry about the end result, as I set it up once and it worked for the entire project.

So, Scenes divide your project into multiple individual Render setups, while view layers divide the scenes to allow editing different components of a render. Compositing in Blender, while not the most advanced compared to other software is super useful for almost all projects, due to this dynamic with having multiple layers to your image.

Hope that gave some more understanding. Thanks for reading