PBRとSubstanceに興味始めたころから気になっていたAllegorithmicが公開している「Physically Based Rendering in Substance」を英語トランスクリプトしてみました。全編50分あるので時間かかりましたが、4つのパートに分けて例の如くYoutubeの自動字幕機能+自分の耳を使って全英文を起こしてみました。
講演者の口癖「you know, kind of, I guess」等の書き起こしても意味がないフレーズはカットしていますができるだけ再現したつもりです。Substance（Designer, Painter共に）を使用したPBRワークフローおよび英語に興味ある方は（Youtube右下のSubtitles/CC機能をEnglish：ONにして）シャドーイング教材としてご活用ください。
各トランスクリプトした動画
Physically Based Rendering In Substance Vol.1/4（英語字幕付き）
Vol.1は、スライドを使ったPBR基礎に関する説明がSubstance Designer/Painterの実例も交えて行われています。具体的には「PBRって何？（基礎理論、利点、新たにアーティストが行う事）」、「PBRのキー要素（エネルギー保存則、フレネル、ラフネスは一番重要）」、「反射性輝度(Intensity of Reflectivity)を制御する3要素（フレネル角度、ラフネス（エネルギー保存則）、F-Zero（反射性））」の説明がされています。
Physically Based Rendering In Substance Vol.2/4（英語字幕付き）
Physically Based Rendering In Substance Vol.4/4（英語字幕付き）
Vol.4は、前半は「マテリアル表面がメタルか非メタルか？」で分類して、メタル（銅、鉄）⇔非メタル（プラスティック）をSebastian Lagarde氏のブログ情報「Feeding a physically based workflow」を参考にSubstance Painter上でデモをして、後半はSubstance Designer上でCrossbowの幾つかのマテリアル（Wood, Iron、Burlap)を紹介し、Woodのノード構成に焦点を当てて細かな解説をしてくれてます。主にスライドを使ったPBR基礎に関する説明が行われています。
Hello and welcome to using SUBSTANCE with UNITY. In this first video, I'd like to take a moment to talk about the big picture and discuss the overall benefit to using Substance. The number one benefit is productivity: SUBSTANCE provides unique work flow and tool sets that greatly enhances productivity that can't be found anywhere else. Throughout these videos, we'll look at each of these main points you see here: dedicated and comprehensive texture tools, physically based rendering and material work flows, 100% non-destructive. These are foundation SUBSTANCE is build upon and I'll showcase each of these points as we walk through examples in later videos. But for now, let's take a closer look at reducing texture size and in engine texture updates. (0:50)
With SUBSTANCE, you can reduce your texture package size up to 90%. The SUBSTANCE engine will generate needed textures at runtime which means the texture package size can be very light weight and allow for a faster download of your content. This in turn allows you to reach a broader audience. Textures are dynamically resized, this means textures are generated at a given resolution so you have the size you need at maximum quality. SUBSTANCE isn't merely up scaling the textures but actually generating at the resolution requested. This means the SUBSTANCE file contains information to generate several textures at various resolutions all within a single compact file. And again, this dramatically reduces the texture package size as the textures don't exist until they are generated. (1:36)
With dynamic runtime support, you can change the look of a texture to create several different iterations all within the UNITY editor. These perimeters are also accessible in code so you can dynamically change a texture during runtime. This is great for creating user generated content for example. (1:53)
Here is a project that showcases how SUBSTANCE can be used to create user generated content by customizing a character. So here I can come through and I can change the jacket pattern size, I can change the jacket colour, I can go in and change the cap colour, as well as the shirt colour, we also have the ability to change our logos so we can switch between different logos and then also add in some jeans ripping and adjust the size, change our shoe colour, and so on. (2:24)
Here's a different example where we are working within an environment so I'll just select the ground and I can actually change the look of the ground, I'll just dial in some age here, and then we will move into the area and I'll just start to age some of these assets as well, so we'll go ahead and dial in some age here, some more aging on this, we'll also affect the wall. So, here I'd like to just run through an overall work flow and pipeline on how SUBSTANCE work, how it relates to your 3D programs and how it relates to the UNITY game engine as well. (2:58)
So, when you're starting on the assets you'll probably start here on the modelling phase, you'll be doing some UV mapping, you've got sculpting and re-topology, uh also animation here will be into that category as well when we're talking about your DCC application. So as you're going through this process you're creating high-reso and
low-reso models, what you can then do is that it will export those high and low reso models over here to SUBSTANCE's designer where SUBSTANCE DESIGNER will allow you to do all of the baking. (3:24)
So here we've got our detailed normal maps, displacement curvature, ambient occlusion, world space normals, position and so on. And so one of the key benefits to using SUBSTANCE with UNITY is that SUBSTANCE DESIGNER's baker tools uses the same tangent bases as UNITY so you get a really great synced normal work-flow between UNITY and SUBSTANCE DESIGNER since they're using the same tangent bases. (3:45)
So once you also start to create a lot of these model bakes here, you can then move on over to SUBSTANCE DESIGNER, you're starting to go through the process of texturing, so here we'll be talking about creating our dynamic textures, animate-able properties, dynamic resizing, procedures working with the full material work-flow and you get in that fast texture iterations that we have. We also have the ability to work with SUBSTANCE PAINTER, so in this process you may actually take your objects and start to bring them into SUBSTANCE PAINTER where you could work through 3D painting, you can paint it across multiple channels, and you can then also work between SUBSTANCE PAINTER and DESIGNER very interchangeably. (4:24)
So you may use SUBSTANCE PAINTER to create various mask, that you will then import right into SUBSTANCE DESIGNER for the mask generators, you may want to create your base materials and things like that in 3D, using 3D painting inside of SUBSTANCE PAINTER. So at this point, the key difference between SUBSTANCE PAINTER and SUBSTANCE DESIGNER: So, SUBSTANCE DESIGNER is going to create the SBSAR file, this is going to be the actual SUBSTANCE material that you then import directly into UNITY. (4:56)
SUBSTANCE DESIGNER is where we’re going to actually create all of our tweak-able parameters here in the middle of properties and dynamic textures and so on. Now SUBSTANCE PAINTER is actually going to export bitmaps for us. So again like I said we can use that directly in SUBSTANCE DESIGNER, we can take these bitmaps, directly into Unity or again we can use those back into our DCC application as well. (5:20)
So another key benefit to SUBSTANCE is that SUBSTANCE has native support within very popular 3D applications such as Maya, 3DMax and MODO. So the same SBSAR file that you are using within UNITY you can also take that back into your DCC application so you could actually preview these materials if you want to go back into that stage where you will be making some modelling adjustments you want to see, how these SUBSTANCE materials are affecting the model. You can actually import that directly into your 3D application as well, so you have that what I like to call a material or texture parity between your DCC applications, SUBSTANCE and UNITY. (5:59)
Over the next few videos we’re going to take a look at how I created this asset using SUBSTANCE PAINTER and SUBSTANCE DESIGNER. We’re also going to take a look at how the SUBSTANCE materials works in UNITY and we’ll take a look at how we can use the procedural material API to make changes to our textures dynamically at runtime.
