Requesting ideas for luminosity, pure colour output

Started by Matt, January 01, 2022, 09:21:27 AM

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Matt

Quote from: WAS on January 01, 2022, 08:53:09 PMAnother name I want to spit out which is kinda unique is "Radiant Shader" which could be dealing with the radiance of albedo, or emission of something.

"Radiant Shader" seems like a reasonable option, one for the shortlist. But "albedo" is reflectivity, which is not what I'm asking about.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Different "configs" you can call from context or palette seems like the easiest way to implement this, and also simple to draw upon. It does make the documentation more confusing, however.

WAS

Also I don't think albedo is reflection at all, that's exclusive in refraction, albedo is the "radiation" of the sun, or light off surfaces. It allows us to see them. Other DCC use albedo exclusively for colouring, where reflections are reflections. In TG surfaces have radiation regardless of a reflection shader when there is light.

Think of a matt surface, it has radiation, buy its not reflecting/deflecting rays like in refraction.

Matt

Quote from: aknight0 on January 01, 2022, 11:41:39 AMColour Data shader maybe?

Maybe. But for me this name implies it should only be used for data output, not for texturing the background or something like that. I suppose if it were combined with @cyphyr idea of a tie-in with Render Elements then it would be a good name. That feels like a bigger feature request though, and adds yet another shader that's overpowered for some of these use cases.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Quote from: Matt on January 03, 2022, 01:17:09 PM
Quote from: aknight0 on January 01, 2022, 11:41:39 AMColour Data shader maybe?

Maybe. But for me this name implies it should only be used for data output, not for texturing the background or something like that. I suppose if it were combined with @cyphyr idea of a tie-in with Render Elements then it would be a good name. That feels like a bigger feature request though, and adds yet another shader that's overpowered for some of these use cases.

Colour in general is weird when it comes to light. Light is not coloured, it's a spectrum of light frequencies, which are interpreted different by different sources (camera sensors, human eyes vs a birds eye, etc). They can all perceive these as different "colours" because they aren't actually colours.

Matt

#20
Quote from: WAS on January 03, 2022, 01:07:37 PMAlso I don't think albedo is reflection at all, that's exclusive in refraction, albedo is the "radiation" of the sun, or light off surfaces. It allows us to see them. Other DCC use albedo exclusively for colouring, where reflections are reflections. In TG surfaces have radiation regardless of a reflection shader when there is light.

Think of a matt surface, it has radiation, buy its not reflecting/deflecting rays like in refraction.

Reflection doesn't just mean specular reflection, it can also mean diffuse reflection. 'Albedo' is the proportion of diffuse reflection, but in some disciplines such as computer graphics the term is applied to non-diffuse reflection as well.

Albedo:
https://en.wikipedia.org/wiki/Albedo

Specular albedo:
https://www.cs.cmu.edu/afs/cs/academic/class/15462-f09/www/lec/lec8.pdf (PAGE 11)
https://docs.unity3d.com/Manual/StandardShaderMetallicVsSpecular.html

Albedo affects how the object appears to us, but only when it's hit by light from elsewhere. If you put an object in the dark, its albedo makes no difference, it will look black no matter what the albedo is. So albedo is not what I'm not asking about; I'm asking about emission.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

I thought you were talking about both a constant coloured surface, and optionally emission if enabled. Emission seems irrelevant here, in regards to albedo as that's a source dispersing rays itself (and in most computers graphics don't even relate unless you're using albedo as a base colour for emission [from a solid surface]).

Matt

#22
Quote from: WAS on January 03, 2022, 02:04:13 PMI thought you were talking about both a constant coloured surface, and optionally emission if enabled. Emission seems irrelevant here, in regards to albedo as that's a source dispersing rays itself (and in most computers graphics don't even relate unless you're using albedo as a base colour for emission [from a solid surface]).

Usually a "constant shader" means a shader that is purely emissive, and that's what I'm talking about.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

When I think "emission" I think you're just saying a luminous surface, if so, why not just Luminous Shader to go in line with the naming used in other shaders already (luminosity)?

What I thought you meant was something like a surface layer, but only handles a coloured surface, or emission (luminosity).

But it sounds like you mean just a emission shader which doesn't interact with TG's lighting models (receive lighting/shadows), but adds to it?

Matt

Quote from: WAS on January 03, 2022, 02:34:16 PMWhen I think "emission" I think you're just saying a luminous surface, if so, why not just Luminous Shader to go in line with the naming used in other shaders already (luminosity)?

What I thought you meant was something like a surface layer, but only handles a coloured surface, or emission (luminosity).

But it sounds like you mean just a emission shader which doesn't interact with TG's lighting models (receive lighting/shadows), but adds to it?

Yes, that's exactly what I mean. "Luminous Shader" is one that I had in mind but wanted to hear it from one of you.
Just because milk is white doesn't mean that clouds are made of milk.

cyphyr

Would your intended "Luminous Shader" effect its environment?

Could it be used for illuminated windows, street lights etc?
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Matt

#26
Quote from: cyphyr on January 03, 2022, 02:51:47 PMWould your intended "Luminous Shader" effect its environment?

Could it be used for illuminated windows, street lights etc?

Yes. It would behave exactly the same as a Default Shader with only luminosity, or a Constant Shader with a function input.

EDIT: Unlike the Constant Shader, though, maybe it should have a mask input and be able to pass through (blend) its main input when the mask says it should. Some shaders still don't have this, but maybe they should.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

This sounds like a good idea.

I also +vote just Luminous Shader to be different from "Emission" in like every other DCC (and also in line with naming already used). If not Luminous I still like Radiant Shader.

digitalguru

The main reason I would use such a shader would be to render an image for vector/scalar displacement - in which case "Luminous" would be slightly misleading if I was coming to Terragen fresh (even more so for "Radiant"). Perhaps the best option would just be to add an input to the Constant shader? And an emission only switch in the default shader for other purposes?

sboerner

First I want to second Dune and Hannes' comments that (for me too, at least) such a shader isn't needed. I always tab through the Default shader before using and zero out the settings I don't need. But it sounds like the proposed shader wouldn't replace this, and that I could keep working as before.

I do think a dropdown "preset" menu in the Default shader would just introduce another level of complexity. A separate shader would be better.

My vote would be for Luminous shader.