building custom plane: is there an addTriangle() order?

[stormp]

Hi,

I was experimenting with building a custom plane.  Is there any order which the addTriangle() or the vectors must be added?

This works:

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objSurface.addTriangle(new SimpleVector(-8.0f,  8.0f, 0.0f),
                       new SimpleVector( 8.0f,  8.0f, 0.0f),
                       new SimpleVector( 8.0f, -8.0f, 0.0f));

objSurface.addTriangle(new SimpleVector( 8.0f, -8.0f, 0.0f),
                       new SimpleVector(-8.0f, -8.0f, 0.0f),
                       new SimpleVector(-8.0f,  8.0f, 0.0f));


Where as this doesn't work:

Code Select Expand

       
objSurface.addTriangle(new SimpleVector(-8.0f, 8.0f, 0.0f),
                       new SimpleVector( 8.0f,  8.0f, 0.0f),
                       new SimpleVector( 8.0f, -8.0f, 0.0f));

objSurface.addTriangle(new SimpleVector(-8.0f,  8.0f, 0.0f),
                       new SimpleVector(-8.0f, -8.0f, 0.0f),
                       new SimpleVector( 8.0f, -8.0f, 0.0f));



Can someone explain?

Thanks.

[EgonOlsen]

Can someone explain?

The docs for addTriangle already do so:

The vertices have to be defined counter-clockwise because jPCT backface culls them by default.

Your second code works...it's just that the object will be visible from the other side.

[stormp]

Doh! I cant believe i didn't notice that.  thx.