Change all shaders default SSS radius to a realistic value
It's strange how SSS is pre-set by default in cycles shaders. By now, the default values are with radius of size 1,1,1. As I now validate a lot of models from different users to our database, I could probably write a '5 top most repeting mistakes blender users do' and not setting a proper SSS radius would be one of them.
I can see that literally no-one from the beginner to semi-advanced level users know what the SSS radius means, and leave it as it is, or think it's color*radius. If the defaults would be 0.02 or something similar, (2 cm) The SSS would work just fine for most of the users without knowing. I
think 2 cm would probably be a reasonable median value in real world. What users now do, they simply set a very low SSS level, which besides not producing realistic results, denoises ultra-slow.
With a reasonable radius value, Cycles denoises exponentially faster.
It's instant improvement of work of many beginner-to-intermediate users, without letting them know about it , similar as to what happend when the default shader in Cycles materials was swapped to Principled ;)
5 Comments
Well, a standard where 1 blender unit= 1m is the default setting if you switch on units, and to my experience, it's used the most, but as you say, not everyone uses it this way. But I think users have same artistic freedom whether they start with whatever setting. Can you explain what type of artistic freedom it brings to have it this way?
A small example to why setting defaults to standards or reasonable physical values might be useful- from 2.79 I saw many cases where users created very dark glass objects. This was simply because the color of glass shader was grey by default, out of the values where probably most glass objects in a household or city are. In 2.8 , glass shader is white and this 'dark glass syndrome' simply doesn't happen anymore, allowing the beginners to overcome one of the thousand steps needed to learn 3d. This change did happen, it brought obvious improvement, did cost nothing ;)
Maybe that some people will understand those specific values like restrictions and will not try to overpass them at the beginning, not everybody of course but it was my case when Ive started. Its a personal thought :)
As for your example, I havent seen it with that perspective! It was effectively a good improvement so maybe changing those default radius values could be working just fine as well.
Yeah nice. I fully endorse the default values on anything in Blender to be set in a way that will operate best for most common use-cases. Otherwise you need to intimately understand every feature to set them correctly, and do it every time you use them. Knowing how to use your tools is important...but so is intuitiveness. The power's there for those who want it, and it's easily accessible for those who don't.
As you already said, the result of the SSS shader entirely depend of the actual size of your model (like all volumetric shaders). But since not everybody modelize everything at the same proportion or just know that the default grid measurement is metric, it would make no sense to have "realistic values" by default. This way you consider that everybody have to keep real proportions everytime we want to make something and afaik, you will have quite a lot of people that will not agree with that. Also, I think that its confusing enough to deal with SSS when youre new to shading. So its good to keep a bit of obvious artistic freedom.
Having said that, I agree that it would be nice to have an option like "use realistic values for volumetric shaders" in the "Render" menu or in the "Settings" panel in the "Material" menu.
* @Shimoon * The default should always be "modeled in a realistic scale" not "people can do what they want any maybe some even do". If you want consistency and predictablility you need to keep size and values in mind and that means modeling to real world scales is the more logical approach.
I also do have to model a lot of my meshes in a larger than realistic scale but I know that the scale I'm modeling at is shifted and I expect to shift default values accordingly.