Adds tree fading based on camera line of sight.
Trees now fade out when they obstruct the player's view,
improving visibility.
Also includes several fixes:
- Fixes tree distribution.
- Adds a see-through shader.
- Adds camera and occlusion scripts.
Implements bush and flower spawning on ground tiles based on vegetation density.
Adds new assets for bushes and flowers, and introduces multi-mesh rendering for optimized performance.
Introduces seasonal color variations for vegetation using a shader for bushes and materials for flowers and grass.
Refactors material application into a MaterialManager to handle material assignments over multiple frames.
Moves ground tile scripts into a subfolder.
Adds floating particles to test scene.
