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[autophile]

Hi all,

I'm struggling to come up with an explanation for why a shape looks white in a scene with a red ambient light and without the shape having any material or texture (source attached). Any ideas?

Thanks,

--Rob

[Patheros]

I took a look at your source, you need to enable light. this is how I do it

Code:

      RenderOptions options = new RenderOptions();
options.setOption(Option.USE_LIGHTING,true);
env.getCanvas().setRenderOptions(options);

Make sure you do this after

Code:

env.addCanvas(Canvas3DFactory
                .createWindowed(800, 600, "My empty scene"));

I did that to your code and uncommitted the appearance section and it seemed to work. I don't know why the default material doesn't appear to be lite properly.

[Marvin Fröhlich]

Strange, that that helped. Lighting is enabled by default.

And ti is a good habit to not create a new instance of RenderOptions, but to resuse the existing one. Maybe the instance has been modified somewhere. So, if lighting is not enabled for some reason, enable it like this:

Code:

canvas.getRenderOptions().setOption( Option.USE_LIGHTING, true );

Or even better:

Code:

canvas.enableLighting();

Marvin

PS. Unfortunately I have no time today to have a look at your source. But I will do tomorrow.

[autophile]

Sorry all, I should have been more explicit -- I'd like to know why OpenGL renders the cube as white (1) without a light, and (2) with a red light.

--Rob

['n ddrylliog]

Sorry all, I should have been more explicit -- I'd like to know why OpenGL renders the cube as white (1) without a light, and (2) with a red light.

--Rob

Simple : your Shape3D needs an Appearance with a Material with lightingEnabled = true to be affected by the lighting :

Code:

shape.getAppearance(true).setMaterial(new Material(true));

Enjoy !

Amos

[autophile]

Okay, I understand that, now. So.. why does the object appear white instead of black or invisible when it does not have a material?

Thanks!

--Rob

[Marvin Fröhlich]

Okay, I understand that, now. So.. why does the object appear white instead of black or invisible when it does not have a material?

That's simply, how OpenGL handles this case.

Marvin

['n ddrylliog]

Yep :
- The object is white so it won't appear black since its basic color never gets modified during the rendering
- It won't be invisible : that would need an Appearance + TransparencyAttributes