Dear Group

I am looking into using tmesh.cal in order to map patterns onto polygons with a Radiance converter that I have written. In tmesh.cal, it defines the first argument as :

A1 = Major axis (0==X, 1==Y, 2==Z)

I have no clue to exactly what this is. Could anyone *coughGreg* provide an explaination of this.

Thanks

Marcus

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Hi Marcus,

The "major axis" is the dominant component in the surface normal vector (the axis with the largest absolute value). Since barycentric coordinates are defined in two dimensions, I throw away the major axis direction as it is the one most perpendicular to the plane of the triangle, and I just use the other two. This is no less accurate than doing a fancy projection and a whole lot cheaper.

The functions defined in tmesh.h and tmesh.c in src/common/ should help you out.

-Greg

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From: "Marcus Jacobs" <[email protected]>

Date: March 2, 2004 11:31:17 AM PST

Dear Group

I am looking into using tmesh.cal in order to map patterns onto polygons with a Radiance converter that I have written. In tmesh.cal, it defines the first argument as :

A1 = Major axis (0==X, 1==Y, 2==Z)

I have no clue to exactly what this is. Could anyone *coughGreg* provide an explaination of this.

Thanks

Marcus