Author Topic: I just want to expose the roughness parameter...  (Read 2936 times)

Ok, so.. full disclosure, I do not know a great deal about this program.  It is, unfortunately not even remotely intuitive, and while there are a wealth of tutorials out there, my frantic workload has thus far precluded me from being able to set aside sufficient time to go through them.

My aim is to try a proof of concept substance to determine if Designer can have a place in our workflow with VizRT.  The sample .sbsar files I load into Viz have adjustable parameters for many values, but the most important one for this purpose is 'roughness', which gives the substance's 'faked' reflection the ability to go from mirror like to highly diffuse.

What I need to do, however is create a new .sbsar file from scratch and have at least that parameter (though hue shift would be nice too) exposed so that I can dial in the look in Viz.  The model to which this substance will be applied is an F1 car.  Here's what I have done:

I created a new metallic/roughness substance, made a BitMap node and loaded the UV texture for the car into it.  I have connected this node to the Base Color and Metallic nodes, and frankly in this state, it is pretty much what we want.  However, I am unclear as to what I need to attach to the 'roughness' output mode in order to have the ability to expose the roughness parameter when I publish the substance to a .sbsar file.

I feel like I can't find a specific bit of instruction for this because it is a very basic function, but my deadline for this project is super tight, and there are many areas of it which require my time and attention.  I thank you in advance for any help you can give me in uncovering this most rudimentary of secrets.

Cheers,
 - Will

Hey w.frazier,

if you just need to adjust the roughness as you said (from glossy to matte) you can simply expose a grey scale value and adjust that in your target application.
We can go through exposing parameters just now. Just the basics and the simplest method to create a Roughness-Slider which goes from black to white (gloss, matte).

1. Create a uniform colour node by either clicking on 'Clr' in the node tab or spacebar -> uniform colour
2. set the uniform colour to grey scale
3. Next to 'Output Colour' click on small function-button (screenshot 1)
4. Click on 'expose' and you are able to set a new name or choose the default one

After doing that you can see that the grey scale slider is gone. That's normal when exposing parameters
You can access exposed parameters by double-clicking empty graph. At the bottom of the parameter panel you can find all exposed parameters in the 'Input Parameters' Tab.

The output of the uniform colour node can now be fed into the Roughness graph output. You will now find a slider with the given name in your target application, when using the published Substance.

I hope that helped and if you still have questions: Feel free to ask them here on the forums!


Best Regards
Environment Artist - Twitter

Thanks Fabian, that appears to have worked... although when I adjust the value in Viz, the change is not that subtle, not like I recall it being with the pre-built substances, and I find that the value seems to increase the overall brightness of the texture (making it look quite blown out at higher values), almost as if the blending more were additive rather than multiply - to use a term from a layers paradigm.

Also - I am finding that the Game Textures Parts 1 and 2 that I downloaded are all .sbsar files with no editable .sbs files... a co-worker has those as .sbs files, but I think his license is pro vs my indie license... is that a limitation of indie?  I ask as those pre-built sbs files make for a good starting off point.

Finally - I upgraded to 5.3 today, and get a crash dialogue every time I quit the program (OSX 10.10.5).  Is that a known issue?

Thanks again.

Hey w.frazier,

can you provide a screenshot or multiple screenshots? I have no idea how 'Viz' looks or if it is something you can actually change, I'm sorry.

The GameTextures pack, however, should contain all .sbs files if downloaded from the Allegorithmic Website, even when downloaded with the Indie license.
I will check back with a developer if the issue is a known bug.


Best Regards
Environment Artist - Twitter