Reflection erroneously shows sky when blending between probes

[atirut-w]

Tested versions

• Reproducible (and can be discovered) in v4.4.dev7.official [46c8f8c], possibly exposed by Add Blend Distance property to ReflectionProbe #99958

System information

Godot v4.4.dev7 - Fedora Linux 41 (Workstation Edition) on Wayland - X11 display driver, Multi-window, 1 monitor - Vulkan (Forward+) - dedicated AMD Radeon RX 6700 XT (RADV NAVI22) - AMD Ryzen 7 5700X 8-Core Processor (16 threads)

Issue description

I discovered this issue when playing around with dev 7 to see how well #99958 works and discovered this bug where the reflection from probes show the sky when blending between probes.

2025-01-03.21-17-16.mp4

Steps to reproduce

1. Set up a scene with overlapping probes with the sky occluded
2. Add in something with 0 roughness and 1 metallic

Minimal reproduction project (MRP)

probe-blending.zip

[lander-vr]

This was already the case before that PR, but since probes would never reach full strength the sky was always blended in, so that transition wasn't as obvious, the sky was just everywhere :)

#100241 fixes this, and you can see the same error as you have in the "this pr" video on this comment: #100241 (comment)

Those ambient light streaks you're seeing in the scene are the same as #99718, I haven't found the cause of this yet.

Your MRP on the priority PR branch: