LineMaterial: Set needsupdate when changing worldUnits property

[dsafa]

Related issue: n/a

Description

I think that it can be confusing that changing worldUnits doesn't affect anything in the rendering. The other properties dashed and alphaToCoverage set needsUpdate when they change

[Mugen87]

If you want to add this, please remove below lines from the examples:

three.js/examples/webgl_lines_fat.html

Line 231 in 04961be

matLine.needsUpdate = true;

three.js/examples/webgl_lines_fat_raycasting.html

Line 310 in 04961be

matLine.needsUpdate = true;

three.js/examples/webgl_lines_fat_raycasting.html

Line 313 in 04961be

matThresholdLine.needsUpdate = true;

[dsafa]

updated

[WestLangley]

@Mugen87 I had some implementation concerns in #26720 that were not addressed. This PR is proposing to repeat those code patterns. I'm just checking to see if you OK with the file as it is currently written.

[dsafa]

I will add, it took me a bit to parse the ( value === true ) !== this.value check. But I decided to just follow the existing properties. I can switch it to just a plain value !== this.value check or even the previous Boolean(value) !== this.value is much easier to read

[Mugen87]

@WestLangley I just think it makes sense to align the worldUnits setter to dashed and alphaToCoverage.

[WestLangley]

@Mugen87 I agree with that. I had questions about the coding patterns introduced in the earlier PR. I was hoping you would comment on my concerns.

[Mugen87]

It's a bit of a subjective matter but imo #26720 made the readability in the file worse. However, if we want to use getters/setters in LineMaterial, we need certain checks that were previously not required (because the properties were defined after the ctor call). I would rather say that's a problem of ShaderMaterial's design in general.

[WestLangley]

@dsafa @Mugen87 Thank your for your responses. It appears we are in agreement regarding the readability of this pattern:

if ( ( value === true ) !== this.worldUnits )

I'd add to that, the unfortunate necessity of this pattern:

if ( ! this.uniforms ) return;