Change emissive factor in js

[Thyronia]

Hello everyone !

I've been trying to change the emissive factor in my script but I can't find a way to do it...

The code so far :

var emissive = [255,0,0];	
modelViewer.model.materials[2].emissiveFactor = emissive;

modelViewer.model.materials[2] refers to the correct texture (I can change the base color without problem for example).

Does anyone know how to change this?

Thanks a lot !

[slightHYP]

I used the setter function to apply the new value.

In your case it should be something like this:
modelViewer.model.materials[2].setEmissiveFactor(emissive);

[Thyronia]

Thank you so much ! I couldn't find this kind of info in the docs, can you tell me where you found this?

[slightHYP]

I had your same problem some months ago, so I had a look at the source code. In particular inside this script:

https://github.com/google/model-viewer/blob/master/packages/model-viewer/src/features/scene-graph/api.ts

here I found what is currently exposed by model-viewer.

@elalish Is this the correct script that provides an overview of all the public available features, methods and attributes? Is it correct, right?

[Thyronia]

Great, I see it ! Thank you again :)

[elalish]

Yes, that's right. We need to update the public docs.

[gabrielgaldinomagalhaes]

Does the emissive lights the other pieces of the object? I mean, if I have the model-viewer exposure set up to 0, and a glb with a black box and a sphere inside of the box, if my sphere has an emissive material, should the sphere light the box ?

[gabrielgaldinomagalhaes]

Alright! I got it! I used an emissive texture inside of the material, and it work kind the way. But now I want to change the emissiveIntensity of these emissive texture of this specific material.

I was testing some approaches and identified that, on console, when I use:
modelViewer.model.materials

If I reach the material index 1. I can reach the emissiveTexture inside of this material (using model.materials[1].emissiveTexture, there is no error in the console).
But once I tried to reach something inside the emissiveTexture that is inside the material[1], it gives me "undefined".

In the console I can see that inside the emissiveTexture there is a set of materials, and inside of this set I can see the emissiveIntensity.

If I change this value using bruteforce straight in the console it works, in the way I wanted it to work (see the screenshot bellow).
Is there anyway to reach the emissiveIntensity that is inside the materials that are inside the emissiveTexture? I don't know if you get it.

But check the console prints that I sent bellow.
In the printscreens you can see me reaching the value I want, on the console, but I can't do that using codes. Because once I try to get something inside the model.materials[1].emissiveTexture, it gives me "undefined".

In this image you can see the emissiveIntensity as 1, and the result in the object. Dark!

In this image you can the emissiveIntensity as 100, and the result in the object. A lot lighter!

[gabrielgaldinomagalhaes]

According to what I see in the structure in the console, I could reach that using something like this
modelViewer.model.materials[1].emissiveTexture.materials[0].emissiveIntensity

It work till here, modelViewer.model.materials[1].emissiveTexture
But once I try to get something inside the emissiveTexture, it gives me undefined!

[elalish]

Any time you see a Symbol, you've left our public API - please refer to the docs: https://modelviewer.dev/examples/scenegraph/#pickMaterialExample - scroll down and you'll see this is accessed via modelViewer.model.materials[1].setEmissiveFactor(rgb);

[gabrielgaldinomagalhaes]

Thank you for your reply, yes, I saw the setEmissiveFactor(), I tested it already! But it allows me to change only the RGB and not the intensity itself. I reckon it would be a 4th parameter in the function. And was exactly after the setEmissiveFactor() that I thought changing the intensity would also be possible. So it is not, not straight on model-viewer, right ?

[elalish]

Did you try values > 1?