The ribbon particles no longer cast shadows.

[fabiopov]

Hi everyone, I noticed that starting from version 5.4, ribbon renderers no longer cast shadows. Until version 5.3, everything was working perfectly.

I have no idea why this is happening. I tried to fix the issue by changing the render settings in multiple ways and using different materials, but the problem persists.

Could this be a bug?

[brs-sebascova]

Greetings @fabiopov!

Another thread with a similar issue presented a solution below, please test it for yor scenario:

@EliasWick

In Unreal Engine, the “Cast Shadow” property can be accessed via Blueprint by using the “Set Cast Shadow” node.

Here are the steps to do this:

1. In your Blueprint, add a “Set Cast Shadow” node.
2. Connect the output of your Niagara System to the “In Particles” input of the “Set Cast Shadow” node.
3. Add a “True” value node and connect it to the “Cast Shadow” input of the “Set Cast Shadows” node.

This will set the “Cast Shadows” property of your Niagara System to “True” by default every time it is activated.

[fabiopov]

Thanks,
but unfortunately, this is not my case. The particle systems are not created at runtime; they are present from the beginning.

The sprite renderer casts shadows as expected, but the ribbon renderer is completely ignored.
Both the sprite renderer and the ribbon renderer use the same material.

In the screenshot, the scene is shown in Light Only visualization mode.

[fabiopov]

I think I have found the cause of this problem.

It looks like hardware ray tracing does not support ribbon shadow rendering.

[pirator]

Have had the same issue.

Not sure if your project allows but try Vulcan in project settings.

Switching to DirectX11 got shadows back - but everything else looked trash.
Switching to Vulcan got it working but only with area lights - which is good enough for me, does feel like a bug otherwise.