Add example to demonstrate manual generation and UV mapping of 3D mesh (generate_custom_mesh) solve #4922

[Adamkob12]

Objective

• Fixes Add an example that demonstrates how to set the texture of 3D meshes from images #4922

Solution

• Add an example that maps a custom texture on a 3D mesh.

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Changelog

Added the texture itself (confirmed with mod on discord before it should be ok) to the assets folder, added to the README and Cargo.toml.

[github-actions]

You added a new example but didn't update the readme. Please run cargo run -p build-templated-pages -- update examples to update it, and commit the file change.

[alice-i-cecile]

Can you swap to a more descriptive title? :) This won't be very useful when looking at the git log or commit list.

[nicopap]

This is worthwhile. I don't think we had an example demonstrating how to create and edit meshes before. It's nice to show how to access and set mesh attributes. Very important, as it's something I'd suspect everyone making a 3d game would need to eventually do.

What I'd like to see

So what needs to be done:

• Rename the example to something more descriptive
• Remove the assets/textures/custom_image_for_example.png and use
  array_texture.png in the example instead.
• Fix the direction labels in comments
• Fix wording in "see docs"
• (optionally) a very small bit of "update the UVs to different values when
  a key is pressed" in the example, this would also showcase how to edit
  an existing mesh.

[github-actions]

You added a new example but didn't update the readme. Please run cargo run -p build-templated-pages -- update examples to update it, and commit the file change.

[Adamkob12]

Changed the texture, added a toggle to switch between textures, clean up & format

[alice-i-cecile]

Thank you both for your patience and thorough work on this!

[Selene-Amanita]

I put a lot of nitpicky comments, but I'm actually pleased by this example even if we ignore my proposed changes, it looks really nice and is pretty clear, looks good to me (modulo typos), good job!

[Adamkob12]

Sorry for all the typos, I swear I read these back but it's like I'm blind to them...
PS: When I commit a lot of changes one by one, do you get spammed with notifications? I'll try to do it all in one commit in the future if you do.

[alice-i-cecile]

Awesome work, merging now!

[Selene-Amanita]

Sorry for all the typos, I swear I read these back but it's like I'm blind to them... PS: When I commit a lot of changes one by one, do you get spammed with notifications? I'll try to do it all in one commit in the future if you do.

No problem for the typos, happens to everybody

I think I have notifications but it's not really a problem and it can probably be changed in settings, do what it takes to make the best PR you can don't worry about that ^^