Style consistency pass on Spatial, Fog, CanvasItem, Sky, Particle shader pages

[tetrapod00]

Resolves https://github.com/godotengine/godot-docs/issues/9745 Also looking at the text in https://github.com/godotengine/godot-docs/pull/9691 as a guide for some of these changes.

Formalized style guidelines:

• Use sentence case for built-in descriptions. Avoid random capitalizations and title case.
• Shader built-ins should always be styled as code: VERTEX.
• Built-in bool descriptions should start with "true if...", "true when...", etc.
• Literal values should almost always be styled as code: 1.0, false, ENUM_VALUE. Ints are 1. Floats are styled as 1.0. Exception: listing ranges in built-in descriptions can be styled as "(0..1)" even if floats.
• Processor functions should usually be styled as "the light() function" in the body and in built-in tables. Use of "the light function" or "a light function" are also okay, if it improves readability. Avoid "the light() function" (without code style).
• Always capitalize "UV".
• When referring to classes or properties, link to the class reference if possible.
• Use "model space" instead of "local space" or "local coordinates". Exception: refer to "model/local space" at least a couple times to establish the connection. Exception: CanvasItem page consistently uses "local space" and I left it alone, since I'm not deeply familiar with 2D spaces.
• https://github.com/godotengine/godot-docs/pull/9757 may let us standardize completely on "model space" except for in the definition table for coordinate spaces.
• In built-in descriptions, try to describe the space as "in world space". For example: NODE_POSITION_WORLD is "Node position, in world space", not "Node world space position".
• Render modes should be stylized as "using the render mode unshaded", "using the unshaded render mode", or. Avoid "render_mode" in the body of the page.

Other, opinionated, changes made by this PR:

• In description of VERTEX, call it "vertex position" where possible. ctrl+f "position" should surface VERTEX.
• Similarly, get the word "color" into ALBEDO's description somehow.
• Link to Standard Material 3D from Spatial shaders. It's the best documentation for alpha modes among other things.
• A few small style, clarity, or grammar changes

[clayjohn]

Looks great so far! I agree with your style guideline

[tetrapod00]

Does Godot have a standard term for local/model space? Within the Spatial Vertex Built-ins table, I see both "local coordinates" and "model space".

I suppose if both are commonly used, it's better to keep references to both in the docs?

[clayjohn]

• In the descriptions of MODEL_MATRIX and MODELVIEW_MATRIX, refer to "Model/local space". It's fine if "model space" and "local coordinates" are used interchangeably elsewhere if they are established as the same at least once or twice.

I would standardize on "model space" because it matches the naming of MODEL_MATRIX and MODELVIEW_MATRIX. Using the term local space was likely done without much thought

[tetrapod00]

"Local space" or "local coordinates" does match the naming convention for local coordinates in CPU-side transforms. If we standardize on "model space", there should still be a few mentions of "model / local space" to make the connection.

At some point all the different spaces should be documented in one place, so that single explanation can be linked to.

Another complication: the CanvasItem page uses "local space" as the main description. Should a different standard be applied to CanvasItem shaders since they are more of an on-ramp for new shader users?

In any case, I'll put the maximal standardization of "model space" into the draft and we can see how it looks.

[tetrapod00]

This one's ready for review.

I can also clean up the guidelines themselves if we think we'll be reusing them. I think it's a fine outcome if these pages get cleaned up once and we don't formalize the style guidelines anywhere.

[tetrapod00]

I made another round of changes for all of the outstanding comments. Would appreciate another correctness check on the changes!

[tetrapod00]

Besides the resolved comments, I also changed how ranges were described in most cases in the spatial shader built-in tables. Before, a range between 0 and 1 was described as "(0..1)". Now, it's "range of [0.0, 1.0]".

• Use code styling for the literals.
• Use square brackets to describe range, to avoid confusion with vector literals.
• Explicitly mention "range of". It's wordy, but increases clarity.

[tetrapod00]

Oh, forgot to resolve a couple entries in the spatial shaders light() table.

[skyace65]

Thanks!