The shadow_enabled property on Light3D turns off baked shadowmasks as well

[ArtyIF]

Tested versions

• Reproducible in 4.4-dev7 and later
• Not reproducible in 4.4-dev6 and earlier as those don't have shadowmasks

System information

Godot v4.4.stable - Arch Linux #1 ZEN SMP PREEMPT_DYNAMIC Thu, 27 Feb 2025 18:09:27 +0000 on Wayland - X11 display driver, Multi-window, 1 monitor - Vulkan (Forward+) - dedicated AMD Radeon RX 570 Series (RADV POLARIS10) - AMD Ryzen 5 2600 Six-Core Processor (12 threads)

Issue description

Currently, turning off the shadow_enabled property turns off the shadowmask as well. This goes against the property's documentation, which says that it only affects real-time shadows.

Turning off real-time shadows while keeping shadowmasks on is useful for optimization purposes. Currently, the two ways to achieve a similar effect would be:

• Setting the shadow resolution to lowest and the max distance to 0.1 (0.0 sets it to the camera's far plane). This doesn't give as much performance benefits as it can, since the real-time shadow texture still needs to be drawn
• Setting the light baking mode to static. This approach (in its current implementation) disables specular lighting, which can affect the scene's look quite a lot (example from my game No Downforce):

Static light baking:

Dynamic light baking with shadowmasks and real-time shadows "disabled" with the first method:

Steps to reproduce

1. Open MRP
2. Disable shadows on DirectionalLight3D
3. The shadowmask will be gone as well

Minimal reproduction project (MRP)

shadowmarkmrp.zip

[Calinou]

I believe this was done by design. We discussed this during the shadowmask implementation and it was best to proceed this way, as it made the implementation simpler. Also, in terms of discoverability, it's best to have a dedicated property to control shadowmask display behavior.

Instead, there should be a dedicated way to set an "always shadowmask" mode that samples static object shadows from the shadowmask exclusively (regardless of distance), and only samples the shadowmap for dynamic objects that aren't baked into the shadowmask.

See comments in #77284 (especially my review comment there) for details.

[ArtyIF]

I believe this was done by design. We discussed this during the shadowmask implementation and it was best to proceed this way, as it made the implementation simpler.

In that case, for now it would make sense to change the property's documentation to also mention shadowmasks.