Default shader "Base colour"

Started by WAS, August 21, 2020, 12:53:07 pm

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WAS

August 21, 2020, 12:53:07 pm Last Edit: August 21, 2020, 12:59:52 pm by WAS
Why change this to base colour? It really makes no sense. The slider is a diffuse colour. Diffuse to black. Diffusion. The function/image input is the base colour... The sliders function is diffusion.

Now it doesn't make sense when I've got tutorials and videos for people that say "set your base image shader and be sure to set diffusion to 1 for original base colour" and stuff. And after setting the actual base colour/function we have a base colour slider which just blackens it (diffusion to nothing)? Lol for it to make sense it seems it would be a desaturate effect.

Matt

August 23, 2020, 11:21:48 pm #1 Last Edit: August 23, 2020, 11:27:36 pm by Matt
In Terragen 4.5, the Default Shader has been improved with PBR materials in mind:

 - Metalness controls.
 - Diffuse colour is renamed to "Base colour", and affects the colour of the specular reflection used when metalness is 1.
 - Reflectivity is renamed to "Fresnel reflectivity" and defaults to 0.75.
 - Roughness defaults to 0.8.
 - Gamma conversion can be enabled or disabled on the roughness, displacement and metalness images.

It is fully backward compatible with old scene files and materials, but the defaults have changed to be more immediately compatible with imported PBR assets. For example, there is some Fresnel reflectivity turned by default and the default roughness is higher so that you get a good result when applying a roughness map.

To be compatible with PBR assets from a metalness-roughness workflow, the "color", "base color" or "albedo" map is used differently depending on whether the material is a metal or a non-metal. For metals it affects the reflection, not the diffuse. The industry standard names for this parameter are "Base color" or "Albedo".

Terragen's Default Shader shared many of the same features as PBR shaders or Standard shaders in other renderers (but its physical accuracy was quite limited until we added the path tracer). The parameter names (e.g. diffuse and reflectivity) and default settings came from the pre-PBR era. I think it's time we brought it in line with everyone else.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

August 24, 2020, 12:21:02 am #2 Last Edit: August 24, 2020, 12:27:27 am by WAS
Err, but it's still a diffusion map. Albedo is the base color input (definition), commonly known as a diffuse map. For example, if you are using metalness, the albedo is usually defining the diffusion of non-metal surfaces of the material. Even in PBR it's still commonly referred to as a diffusion/albedo map. Even substance on a coding level is calling it "Diffuse". The only reason it's really "Base Color" is because it's a drag-drop layer colouring system, and it's the base one.

And again, the slider is actually doing a diffusion effect, lightening or darkening the map inserted, which is inherently diffusion. It's not doing any "Base Colour" anything. It's diffusing, and the Base Colour Image/Function defined below it. Similar to C4D. You have your Colour, you define with a map/tone, and then the diffuse, which is the lightening darkening of the base color you picked whether via certain areas (masked) or the whole map.

Is this just to be familiar to substance designer users really? And if you're naming it based on an invisible aspect of the metalness function (which is hardly encompassing PBR and really actually a rare material over the natural ones), don't you think that's weird? Especially when in normal circumstances it is just a diffusion slider?

Maybe I'm just getting tired of arbitrarily renaming stuff in the framework, or weird changes. Like now the scientific notation system is double-digit instead of triple which doesn't appear to have been for any real reason. If you're going that far why not single digit; ie 1e+6

Dune

It's not only changing the lightness as a diffusor, I'd say, as it's not just a greyscale slider/input; you can change the color and thus adjust the hue of any input. So for me Base color sounds good, though I wouldn't care less what something is called, as long as it does what I need. My 2 cents.

WAS

Quote from: Dune on August 24, 2020, 01:39:59 amIt's not only changing the lightness as a diffusor, I'd say, as it's not just a greyscale slider/input; you can change the color and thus adjust the hue of any input. So for me Base color sounds good, though I wouldn't care less what something is called, as long as it does what I need. My 2 cents.
That would be saturation. Diffusion is of light. So it's blackening out the albedo to nothing.

And that is all the slider does. No hue adjustments. You have to do that manually. It can take colours over 1 in a 32bit color space