How can I create inputs and outputs for transmission ?

[Forester3d]

I would like to create transmission weights, an input (maybe a slider) for IOR values, and some other properties for transparent materials such as glass. There is an Output Node for Transmissive, but I don't know what information this convesy, and I don't know how to feed it any information.

Are there ways that I could create this kind of transmission information that could appear in a published *.sbsar file?

[Forester3d]

I should amend this question.  I "can" create a set of typical transmission properties for transparent materials such as glass. And these do appear in the *.sbsar file. (And my question about the Transmissive Output  Node is in error. I figured out how to give this a value in the proper range of values. Basically, its just the same as the Opacity Output Node.)

Is there a way these properties could be made to appear in the plugin for Arnold or for Maya-Maxwell Render.

Here is my graph. There is at least one error in this in that the base color and the "Transmission Color" really should be the same thing. But I am uncertain as to how to consolidate these without messing up the required base color.

[Luca Giarrizzo]

Hello @Forester3d,

Thank you for your patience.

I am unsure of what is meant by 'properties' in this context. Would these be exposed parameters in the Substance 3D asset file (SBSAR)?

Best regards.

[Forester3d]

Thank you for your reply.

Yes - "exposed parameters"...

The most problematic issue in making and using "glass" materials in Substance Designer is the inability to transfer information about "transmission" properties of glass to other applications. As you can see in my image illustration below, I can "create" information about the "transmission" variables of transparent materials such as glass in Substance Designer, but there's no good way to get this into other rendering engines.

There are several rendering engines that were and are inherently physically-based renderers, to my knowledge, Maxwell Render and Arnold. These have a few "transmission elements or properties" at their core. That is, Maxwell Render has the two IOR variables, "Nd" and "K" and some others as a component of every material. Arnold is similiar in that it a "material type" of transmission at its core for the standard surface shader. These two rendering engines share a bunch of the basic transmission variables - IOR, Abbe, etc. Other rendering engines that we designed prior to the advent of PBR, of course, use different kinds of things to create a glass shader. For example, Corona relies on "reflection" and "refraction maps" as kind of a stand-in for the basic transmission properties of transparent and semi-transparent materials. I'm not too worried about these earlier rendering engines. But, for the more modern PBR engines, ......

If we were to develop a standardized "node" for Substance Designer that carried the information about these few common transmission variables, such as in the example image below, would it become possible to have these elements picked up as exposed parameters in the Adobe Plugins for Max, Maya, etc, so they could be directly read into Arnold ? (...in addition to the existing Opacity exposed parameter?)  I can make a standard node like this, and Adobe certainly could make a standardized node and publish it in a future version of SD.

Essentially, I'm asking if it is possible in the near future to have a more complete set of exposed parameter elements for "transmission" in the Adobe Plugins so that "glass materials" could be more readily imported into MAX, MAYA, C4D, Houdini, etc. That is, so that Arnold users, and possibly Maxwell users could import SD materials into these rendering engines that would be readily recognized as being "glass" or as "transparent" and "semi-transparent" materials with adjustable properties?

[Forester3d]

My apologies if my question is poorly stated and can't be understood. If this is the case, please let me know and I'll try again.

And thank you very much for the favor of your reply, and for the time you are taking on this issue.

[Forester3d]

This is kind of a "postscript note", but I've just finished writing a set of five tutorials on how to make glass and how to make surface imperfections for glass in Substance Designer. The tutorials are aimed at professionals in the product vizualization, interior design, industrial design, and similar fields. Mostly professional rendering artists and isntructors who have not previously used SD. If it is any help in clarifying my query, I'd be happy to forward copies of the tutorials to you.

[Luca Giarrizzo]

Hello @Forester3d,

Thank you for the detailed answer! I have a better understanding of the issue and hope I can help.

First, please note our integrations do not support output values across the board at this time. Using textures for all outputs will provide the most consistent and reliable experience in third-party software. I will use the Arnold renderer in Autodesk 3ds Max as an example.

In Designer you may create input parameters in the graph's properties and use them to drive textures, as shown in this example.

If you need to work with values instead of textures in Designer, create input values for nodes and use your values to drive parameters, as shown with the Value processor to Uniform color combination in the example. This way the final output remains a texture while you work with values.

In 3ds Max, the Substance for 3ds Max plugin lets us load a Substance 3d asset file (SBSAR), access its exposed parameters and automatically create an Arnold material out of it. Some basic textures will already be connected, and you may easily connect the rest to drive the desired values. This example shows a very simple workflow. See this page for out list of available plugins.

I hope this is helpful! Let me know if you need further assistance.

Best regards.

[Forester3d]

Thank you very much for the answer.

(My apologies for the delay in replying: a family emergency required me to travel to another state over night.)

I appreciate your answer. That clarifies things for me.

I have tried the Maya plugin, but whenever I get to the step of select your Workflow, and click on the button for Arnold, Maya crashes. I'm trying to work through that now, and will experiment with the Max plugin.

Thank you again for your kind response.