Substance and Blender 2.79+

In Blender 2.79, there is a new Principled BSDF shader. This means there’s a new workflow for importing textures from Substance Painter and Substance Designer. The good news is the workflow is very simple. But it’s a new workflow nonetheless.

To loads PBR textures for the Principled BSDF, you’ll need the following channels:

  • Base Color
  • Roughness
  • Metallic
  • Normals (formatted for OpenGL)

You might notice this is the default format for Substance. So if you like, you can just use the “Document Channels” export mode in Substance Painter. Alternately, you can use this Substance Painter export preset. You can add it to your shelf, or see here for creating and installing export presets. Download it here: https://drive.google.com/file/d/0B4md98mV7RHJMGZfZXBuSEx0dU0/view?usp=sharing

The textures are simply loaded and connected to their corresponding sockets. Note that normal, roughness, and metallic must be set to “non color data” to disable gamma correction.

pbr_easy

Other Map Types

Emission

To use emission maps, connect them to an emission node and combine with with the Principled BSDF via an Add Shader:

Transmission (in the sense of “glass”)

The Principled BSDF supports dielectric transmission, so you can hook up your transmission/opacity map directly. Note that the metallic map will “override” transmission, since transmission only applies to the dielectric layer. This makes sense when you think about it for a second, since glass is also a dielectric, and metals aren’t transparent. In a lot of softwares’ ubershaders, however, transmission overrides everything so this might be jarring at first.

Transmission (in the sense of “alpha maps”)

You can use alpha maps by mixing the Principled BSDF with a Transparent BSDF. In this example, our basecolor texture has cutout opacity data stored in the alpha channel:

Ambient Occlusion

You don’t need AO maps in Cycles, ever. Ambient Occlusion is shadows (aka occlusion) for the global “ambient” lamp. Hence the name. Cycles does not have an ambient lamp object. The world light is a physical light at infinity in all directions, rather than an ambient light that adds an even glow to things. There is a “World AO” options, which is technically an ambient lamp with built-in occlusion calculation. There is no option to use pre-baked AO with the World AO function, however. AO maps should never be applied to diffuse or direct lighting, only to the ambient lamp. See this famous blog post for more information: http://mentalraytips.blogspot.com/2008/11/joy-of-little-ambience.html

While AO maps applied to diffuse can be very useful for dirt effects, it is almost always preferable to pre-mix this into the regular basecolor/rough/normal/metal textures, rather than loading baked AO separately and compositing it within the shader. Adding AO dirt during texture painting will allow you to avoid loading the AO map, saving memory. It also allows you to “bake” the compositing operation, as well as having more control over said compositing.

Height/Displacement

Microdisplacement can be used to represent heightmaps with tessellation/displacement. This workflow has not changed since Blender 2.78, and is the same whether you’re using the Principled BSDF or the legacy PBR node groups.

Simple PBR v5

UPDATE

You should use the Principled BSDF shader instead of PBR node groups such as Simple PBR. See https://jtheninja.wordpress.com/2017/05/11/substance-and-blender-2-79/ for more information.


It’s been awhile since I posted a new version of Simple PBR. It’s gone through a couple internal updates (one of which I brought back to v4 because I found it useful). If you want to some techno-rambling about what exactly is changed, I’ll describe it at the end of the post. A lot of you probably just want the shader and some basic instructions, so, here you go:

overview

Download it here: https://drive.google.com/open?id=0B4md98mV7RHJaGFKcVpmVjRvZ0U

There are two main nodes inside, “Simple PBR v5” and “Simple fastPBR v5”. Both give mostly similar results and have the same inputs. fastPBR is slightly faster to render. Not by much, you might not even notice the difference on big scenes, but Simple fastPBR skips a few things to optimize the shader a bit. In exchange for making you wait slightly longer, the regular version will give slightly more realistic results with higher roughness.

IMPORTANT: SIMPLE PBR v5 REQUIRES BLENDER 2.78+!!!! It is NOT compatible with 2.77a!


“Wait!! There used to be a Substance and Substance Painter shader, what do I do now?!”

Simple PBR v5 has transcended such things. You can now just use the regular Simple PBR or Simple fastPBR with Substance. An updated Blender Cycles export preset for Substance Painter is included. If you were using the one that came with Simple PBR v4, you should replace it with the new one. It will export maps for each of the 4 channels. Roughness, metallic, and normalOpenGL should be loaded as “non-color data”, base color should be loaded as the default “color”. You will need to add a normal map node in-between the normal input on the shader and your normalOpenGL image node. See below for the example setup.

Note that now all Simple PBR shaders use squared roughness. This is different from the raw glossy BSDF, but it’s easier to work with and it seems the way all the other community PBR shaders are going.


“How do I use Simple PBR?”

Glad you asked. Append it to your scene and plug it into the material output. Typically your textures go something like this:

example

The only other thing worth noting is that if you are not using a bump or normal map, you will need to manually supply the mesh normal with the geometry node as in the screenshot above (it’s set up in the source file too for your reference). This is due to some limitations with Cycles and node groups not initializing the shader normal properly in some cases, using the geometry > normal output just sets it manually to the correct value.


Simple glazePBR and Simple PBR Glass

Simple glazePBR is just the dielectric reflection component of Simple PBR. You can use it to add a realistic gloss to non-conductive objects that are not diffuse. Like, say, skin. Or you can make some sweet (and easy!) carpaint but sticking it after the regular Simple PBR.

Simple PBR Glass is, well, a glass shader. It was sort of a last-minute addition to the kit. It hit me that I often use a bunch of the same nodes when making glass shaders, which was the same impetus that created Simple PBR in the first place. So meet the refractive member of the family! It has built-in volumetric colors (absorption only! no performance worries here, I checked carefully!). It also will automatically switch to transparent shadows instead of caustics when roughness is set to 0, since Cycles can’t reliably produce caustics from sharp refractions. The “color density” input will adjust the strength of the absorption effect


Did you know that Cycles it getting support for Disney’s “principled BRDF”? It’s true: https://blenderartists.org/forum/showthread.php?403342-Cycles-Disney-Brdf
Once this is done it will more or less render obsolete all these community PBR shaders. There may still be a need for the glass and glaze shaders, it’s something I’ll look into when the time comes.


Finally, if you find Simple PBR useful, I’d appreciate if you could throw some coins in the tip jar in the sidebar



TECHNICAL MUMBO JUMBO SECTION

Ok, so what is actually new in v5? Here’s the important bits, I’ll explain why for each one:

  • Plain “Simple PBR v5” uses the new Multiscatter GGX glossy option in 2.78. This gives brighter, more correct results with high roughness. It comes with a bit of a noise and speed cost, hence the impetus for fastPBR, which uses the old simple GGX.
  • Diffuse roughness is now calculated as glossy roughness * 0.33 instead of using the glossy roughness directly. After actually reading some docs on Oren-Nayer shaders (how useful) I found that most real-world surfaces will not exhibit sigma values beyond 0.5, with most topping out around 0.3. This is something I probably should’ve remembered from my LuxBlend days… Anyway, I thought for awhile on the best way to handle diffuse roughness in Simple PBR. Using glossy roughness directly led to weird velvety-looks with roughness=1. I thought about disconnecting it, or locking it at a value, or exposing it as its own parameter. After awhile, I decided on using the glossy roughness * 0.33. It’s kind of arbitrary, but it gives a decent result in most cases without having to manually set it.
  • Simple fastPBR does not use Oren-Nayer at all, diffuse roughness is disconnected interally and set to 0. This gives a small speedup at the cost of realism on rough surfaces.
  • Roughness is squared in all cases. Most of the community PBR shaders, particularly Andrew Price’s, do this as it’s easier to work with and allows compatibility with most PBR authoring tools. This does mean it gives different results than a bare glossy BSDF, but I think most people will figure it out. Additionally, the roughness squaring is done as roughness*roughness, rather than roughness^2, just to be safe. This does not make a speed difference that I’ve ever observed, but why do things the potentially slower way?
  • Substance Painter export no longer packs roughness/metallic/height to an RGB texture. In 2.78, Cycles adds native support for single-channel textures (grayscale, float, scalar, single, whatever you want to call them). By exporting roughness and metallic into seperate grayscale files, they can be loaded using one channel each, meaning a total of 10 texture channels are loaded. Basecolor and normal both require 4, as Cycles does not have an RGB texture type, just RGBA. The old packed method required initializing a 3rd RGBA texture meaning 12 channels total. So the new method saves you 16.7% texture memory at the cost of making you load a 4th image node. (I recommend the “multiple images” option on the node wrangler addon, btw). Previously, seperate textures would’ve result in their own RGBA textures internally resulting in 16 channels, hence the intial design of the packed version. This is no longer needed.
  • You shouldn’t need to manually disable heterogeneous volumes or transparent shadows with the glass shader. I tested carefully to make sure these weren’t getting kicked on when they weren’t supposed to, and there is no render time difference that I can pick up.