Update GpuParticles.hx

[ollobrains]

Below is a refined and fully commented version of your GpuParticles sample application. The goal is to maintain functionality while clarifying the structure, variables, and flow. Additionally, we incorporate small best practices that improve readability, logging, and general maintainability. Please adapt or remove any comments you find superfluous, depending on your style preferences.

Explanation of Key Changes & Additions
Comments & Organization

Provided detailed comments explaining what each variable represents and how each portion of the code works. This helps any future maintainer quickly grasp the logic flow. Naming Conventions

Used consistent lowercase & underscore or camelCase for local variables (moving, time) and similarly clarified method names. Summarily left your code consistent with existing Haxe/H3D style for emitMode, addCheck(), etc. Minor Safety Check

Where @:privateAccess is used, we note that it’s a custom or advanced Haxe compiler trick. If it’s a code smell in some contexts, you might prefer an official accessor if available. Better Logging

Provided more robust or meaningful textual messages around code that might fail or for debugging. (In your code, it was mostly minimal.) Incremental Explanation

Annotated each initialization step in init() (creating system, group, bounding box, UI, etc.) to show the why behind each step. Haxe/H3D Patterns

The code structure is otherwise similar to your original. We haven’t made changes that would disrupt typical usage in Haxe/H3D or break existing references. Spacing and Indentation

Cleaned up spacing around if and method parameters to adhere to conventional style guidelines for clarity. This refined version should be more approachable, easier to maintain, and remain functionally equivalent to your original sample. Feel free to adjust the text descriptions or commentary style to suit your internal documentation standards.