alpha = 0 not fully transparent

[Numa]

Hi there, 

I'm fading out meshes by setting material.alpha = 0;

However they still appear in the scene. I checked and their alpha is definitely set to 0.

 

Bug? Feature?

 

Thanks

[jschwuch]

Hi!

Can you reproduce it in the playground? I just tested it and they are not visible in my test playground http://www.babylonjs-playground.com/#600LYK#1

If you can't reproduce it and need a workaround. You can set the meshes opacity visibility instead of the materials alpha, maybe that works as expected, ultimately you could set the meshs layermask to zero if it's materials alpha is zero. But those are of course options on a per mesh basis and not per material which may be a problem in your project

I'll try my best to find the problem if you can reproduce it in the playground.

[Numa]

Thanks, I'll try to reproduce it in a playground. It might have to do with animations (I don't set alpha to 0, I animate it). For now my workaround is to call material.disableLighting = true.

[aWeirdo]

@Numa 
While It's hard for us to know whats going on without first seeing a PG replicating the issue,
something that should work however,
is setting the mesh's visibility instead.

e.g. mesh.visibility = number; // ranges from 0 to 1, e.g. 0.5 = 50% visibility.

[jschwuch]

@aWeirdo That's exactly what i wanted to say but i called it opacity as that's what I call it in my project  Sorry for that and thx for your correction 

[jellix]

Is there a special kind of reflectivity or glossyness or metalness on it?

[Numa]

reflectivity yes:

var baseMaterial = new BABYLON.PBRMaterial("baseMaterial", scene);

    baseMaterial.reflectionTexture = hdrTexture;
    baseMaterial.reflectionTexture.coordinatesMode = BABYLON.Texture.CUBIC_MODE;
    baseMaterial.directIntensity = 1.8;
    baseMaterial.specularIntensity = 1;
    baseMaterial.environmentIntensity = 0.2;
    baseMaterial.cameraExposure = 1.4;
    baseMaterial.cameraContrast = 0.95;
    baseMaterial.microSurface = 0.27;
    baseMaterial.reflectivityColor = new BABYLON.Color3(0.2, 0.2, 0.2);
    baseMaterial.emissiveColor = new BABYLON.Color3(0.1, 0.1, 0.1);
    baseMaterial.useRadianceOverAlpha = false;

I'll use visibility instead of alpha then

[Sebavan]

Basically, in real life, highlights can be seen on top of transparent surface preventing to see through like your computer screen reflected on your window shield by night or car shield reflecting sun...

Trying to emulate that, we by default in the material force displaying highlighted part of transparent surfaces (automatically increasing opacity in front of the luminance of the highlights either radiance from environment or specular from scene lights). 

You can disable this by setting those both parameters in the material (they are true by default):

useRadianceOverAlpha = false  and 

useSpecularOverAlpha = false

[Numa]

oh right, that makes sense! that's it, beautiful thank you

[jschwuch]

That's some new info for me too thx @Sebavan !