Spotlights do not work for orthographic projections

[itsybitesyspider]

Bevy version

commit 4f1d9a6 (HEAD -> main, origin/main, origin/HEAD)
Date: Sun Aug 27 07:33:49 2023 -0700

[Optional] Relevant system information

cargo 1.70.0 (ec8a8a0ca 2023-04-25)
Debian 12

2023-08-28T00:41:15.115702Z  INFO bevy_render::renderer: AdapterInfo { name: "AMD Radeon RX 6600 XT (RADV NAVI23)", vendor: 4098, device: 29695, device_type: DiscreteGpu, driver: "radv", driver_info: "Mesa 22.3.6", backend: Vulkan }
2023-08-28T00:41:15.389897Z  INFO bevy_diagnostic::system_information_diagnostics_plugin::internal: SystemInfo { os: "Linux 12 Debian GNU/Linux", kernel: "6.1.0-1-amd64", cpu: "AMD Ryzen 9 5900 12-Core Processor", core_count: "12", memory: "15.5 GiB" }

What you did

Tried to add spotlights (car headlights) to my game project, but they never show up. Finally I added a test spotlight which strangely appeared only toward the bottom of the screen (not across most of the rest of the screen). I think what matters is probably not the bottom of the screen, but the fact that the "ground" is naturally closer to the camera in that region of the screen.

Replicated this problem in the spotlight example (cargo run --example spotlight) by replacing the camera in setup with this camera:

    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(-4.0, 5.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
        projection: OrthographicProjection {
            scale: 5.0,
            scaling_mode: ScalingMode::FixedVertical(2.0),
            ..default()
        }.into(),
        ..default()
    });

What went wrong

Expected: The spotlight should illuminate the scene in the same way it does with a perspective camera.
Actual: It does not illuminate the scene at all, or only some areas of the screen. Correct behavior is demonstrated in the example: https://bevyengine.org/examples/3D%20Rendering/spotlight/

Additional information

Other information that can be used to further reproduce or isolate the problem.
This commonly includes:

• screenshots: I made a gif. The bright flash is the spotlights. If you see a dark flash, that is the gif looping, it doesn't appear outside of the gif.

I wonder if this screenshot is informative. I captured this by taking video and then screen-shotting one frame of the video. It flashes like lightning.

• logs: don't see any interesting logs
• workarounds that you used: Spotlights work fine in perspective projection, point lights work fine regardless.