This article was initially published in DP 06 : 2018.
We’ve already heard about the huge step forward that Unity has made in the last year. Coming with it are new ways of rendering. The results are impressive indeed, and it’s not just game developers who like to use this engine for their games. The automotive industry is starting to knock at the doors of Unity and others are sure to jump on the train as well.
Lightweight Rendering and High Definition Rendering – these are the two brothers who joined the Unity club with update 2018.1. It is easy to guess which one of them serves which purpose, and we had a little chat with Arisa Scott, Graphics Product Manager at Unity Technologies, to find out what makes those two rendering pipelines special and how people have adopted them.
DP: How do you like the event so far?
Arisa Scott: It’s great! It’s been very high energy, I loved the keynote. I knew a few bits of what was going to happen, but I didn’t know, for example, about the game “Harold Halibut” and listening to the guy who was thrilled about the HD Render Pipeline (HDRP) was really great. I wanted to be introduced immediately after to get some customer feedback from them as well.
DP: In your talk, you introduced Lightweight Rendering and High Definition Rendering. Of course, there are differences in performance, but what is the main difference regarding the pipeline between those two?
Arisa Scott: They are built on top of the same architecture, but they are optimized for two different things. The Lightweight Rendering Pipeline is all about being stripped down and optimized for things like mobile performance. It is also more similar to our current renderer, just with a slightly reduced feature set. HD, on the other hand, is very different. It is optimized for GPU, compute-capable, very high-end. When you open it up you have tons of options and settings which you have to dig into a little deeper to fully understand what they are capable of. If you are a graphics programmer, it is a fantastic playground, and if you are an artist, you can just open it up and create something that you have much more control over now. It is much more about creating a visually beautiful, cinematic experience.
DP: What is the main thing that is missing then in the Lightweight pipeline?
Arisa Scott: There are things that were intentionally not added, because if we were to add them, they would hit performance. For example, in our post-processing stack there are options that are not available because of that reason. We do offer some lighter versions of those, but if you have a material in HD that looks gorgeous, you can’t just add that in Lightweight, because the performance would suffer too much and you wouldn’t be able to ship it and hit with 60 fps on mobile.
DP: Is it possible after starting with Lightweight to switch to HD afterwards?
Arisa Scott: You don’t need to start all over again, but you do have to restructure things a little. If you have created your shader with shader graph, we have added a master node that works in both, so you can have your shaders move over. The lighting system is also different. Lightweight has a simplified PBR system, whereas HD is more accurate in addition to having all the shiny things, and HD acts a lot more like real lighting would. So you have to redo your lighting and you probably have to redo some of your materials as well, because you will have many more possibilities to get better quality out of them.
DP: When developing the HD Rendering pipeline, did you take a close look at other products which already support these workflows? Other engines for example?
Arisa Scott: The majority was written by Sébastien Lagarde, an excellent rendering architect who also worked on the Frostbite Engine. So it was a lot about him bringing his industry experience into the project and making sure that we could achieve this cutting-edge quality. But of course, we always keep an eye on the competition as well. Everyone has to.
DP: How did you affect the development of HDRP?
Arisa Scott: I’m bringing in feedback and the customer point of view. You can improve a lot by directly listening and reading what our customers want and need. Lightweight and HD are both in preview at the moment, so we are getting a lot of requests, feedback and wishes. It’s a huge help in terms of optimizing everything and also finding lacks in terms of features which could be better or that have been missing so far.
DP: What did people say so far?
Arisa Scott: I think “Harold Halibut” was actually a good example of the high energy and excitement around it. We are definitely getting a lot of positive feedback. There is another studio I talked to that mostly does TV shows and the most valuable thing for Unity’s new HD Rendering pipeline enables users to get much more high-quality looks. Examples like Toyota’s Lexus LC5OO campaign have proven that Unity can indeed provide the quality necessary for industry standards. them were features like color temperature adjustments and these kinds of things. They are working with directors who are used to talking in a certain language, so what it did in addition was remove those barriers and make it a lot easier for them to be on the same page.
DP: What were the biggest challenges that came up with HDRP?
Arisa Scott: The thing with HD is that we are adding so many features. We have to make sure that we are implementing these features in a way that is accessible for our current Unity users. To not have the risk that it is too overwhelming. Of course, there are a bunch of options that you still need to dig into, but you don’t have to modify anything if you don’t want to. The defaults just have to work. That’s it. Making sure that if you don’t want to change or switch anything, the default options work and it still looks good.
DP: If someone has already worked with other software, is it difficult to adapt to Unity?
Arisa Scott: We try to make it as intuitive as possible. Another thing that is very valuable to Unity is our community. I’d say it is definitely one of Unity’s strengths that we have a great community which is producing a lot of content. I think this makes it a lot easier to actually give Unity a try, because you have all of these tutorials that naturally come with it. And also we have really wonderful technical writers who are doing their best to make sure that all the available documentation for Unity is easy to understand.
DP: Are Lightweight and HD already integrated in the engine or do you have to add them manually?
Arisa Scott: They are included and completely free to use. When you open up 2018.1 for a new project, you will have a list of templates which our lovely tech art team has created. There you can find things like a 2D or 3D template and also the Lightweight and Lightweight VR template. Same goes for HD.
DP: What are your future plans?
Arisa Scott: As I said, both are in preview, so the nearest future goal will be adding more features and working on optimizing everything. Especially for HD there is probably an endless list of high-end things you can add, but basically it all comes down to offering better results and also more control. In 2018.3 we have a new reflection system that will give much better control over all of your reflection props. Minimize light leaking and that sort of stuff. So it’s about finding areas where we are currently missing control.
DP: Do you recommend Unity Rendering to beginners and do you think it can keep up with other applications like Marmoset Toolbag in terms of quality?
Arisa Scott: It depends on what this person wants to achieve. But if you want to get a nice portfolio shot, I would definitely recommend HD, because you don’t have to modify anything, just take a look at all the lights and start playing around. You can grab the “Book of the Dead” reference to see how they have set up their scene and use that as a start to make your own stuff look beautiful.
With HD we are really aiming for the highest end you can get in real-time and it is important for us that we get this top tier support. But to be fair, it’s still in preview and I think we do need to do some more optimization and add a few more features to make it perfect. For one nice shot, one nice rendered picture, I think HD definitely gives you the quality needed for a nice portfolio shot. And especially for game artists it is another plus to show that you can achieve this quality within a game engine.
DP: Is there anything you would personally like to add to the Unity Rendering pipeline?
Arisa Scott: Mhm … not something completely new, but the thing I’m excited about the most in our upcoming versions is the new VFX editor, because it gives you so much freedom and allows you to do so many cool things. It’s a brand new system and not compatible with the old one. They won’t merge, although they are both particles. VFX editor is the successor. Right now it is GPU-use only, which allows the creation of millions of particles, and it has more of a Houdini-like interface, making it much easier for you to create particles, I think.
DP: What are your thoughts on the image of Unity and the direction it is heading at the moment?
Arisa Scott: We are about democratizing development, which means allowing more people to create. When you have a strong vision and strong artists, you can definitely make something beautiful. Bringing more control into your own user space, I’d just say that you are your own limitation. I’m really excited about the direction in which Unity is going with 2018.1 and the versions after that.