CSM Shadow: How to toggle csm shadow

[ligaofeng0901]

Description

(https://jsfiddle.net/ligaofeng0901/yqv21wtp/26/)
This is a modified version of offical example. if you click the toggle button to disable csm shadow, the shadow node can't be disposed, and the shadow is still here.
The main problem is the light node cann't detect the change of shadownode. And as I konw, there is no way to forcely update light. these code light.needsUpdate = true;light.shadow.needsUpdate =true;light.shadow.shadowNode.needsUpdate = true; all don't work.

Solution

Provide a way to forcely update lightnode ?

Alternatives

Additional context

No response

[Mugen87]

Shadows should be toggled by changing the castShadow light property. This is currently broken for CSM shadows though. The PR is trying to fix this.

[ligaofeng0901]

Shadows should be toggled by changing the castShadow light property

Ok，does it mean setting castShadow to false, all shadowmaps of this light will be disposed?

In my app, shadow is a rendering feature, which allows user to enable or disable it dynamiclly, or change the shadow type, csm or default, and other types. If we disable shadow, all associated resources should be disposed.

So when shadow is set from enabled to disabled, I try to set the light.shadow.shadowNode = null; renderer.shadowMap.enabled=false; So far, it doesn't work as expect.

[Mugen87]

Ok，does it mean setting castShadow to false, all shadowmaps of this light will be disposed?

Yes, this happens here, btw:

three.js/src/nodes/lighting/AnalyticLightNode.js

Lines 206 to 220 in b801c8f

	if ( this.light.castShadow ) {
	if ( builder.object.receiveShadow ) {
	this.setupShadow( builder );
	}
	} else if ( this.shadowNode !== null ) {
	this.shadowNode.dispose();
	this.shadowNode = null;
	this.shadowColorNode = null;
	}

[Mugen87]

You can test the changes of #31186 with r177. If things works as expected, we can close the issue. Otherwise you can report your findings here 👍 .

[ligaofeng0901]

You can test the changes of #31186 with r177. If things works as expected, we can close the issue. Otherwise you can report your findings here 👍 .

Thanks for the update! I've tested the changes, and things work as expected so far👍.
I also noticed that you said globally toggling shadows was never an ideal solution in the PR. Out of curiosity, will the global renderer.shadowMap.enabled approach be deprecated in the future? Just want to make sure we're aligning with the recommended usage going forward.

[Mugen87]

No, it won't. My comment just referred to the fact that renderer.shadowMap.enabled was used in the example because it was not possible to toggle CSM shadows so far.