API Reference > geometry-core > ArraysAndInterfaces > GrowableXYZArray > fillLocalXYTriangleFrame fillLocalXYTriangleFrame Method Triangle for (unchecked!) for three points identified by index z direction of frame is 001. Transform axes from origin to targetX and targetY in local coordinates (u,v,w) the xy interior of the triangle is u>=0, v>= 0, w>= 0, u+v+w<1 Return undefined if transform is invertible (i.e. points are not in a vertical plane.) fillLocalXYTriangleFrame(originIndex: number, targetAIndex: number, targetBIndex: number, result?: Transform): Transform | undefined Parameter Type Description originIndex number targetAIndex number targetBIndex number result Transform Returns - Transform | undefined Defined in core/geometry/src/geometry3d/GrowableXYZArray.ts Line 931 Last Updated: 13 June, 2024