An apparatus and method employing principles of stereo vision for determining one or more orientation parameters and especially the second and third Euler angles theta, psi of an elongate object 10 whAn apparatus and method employing principles of stereo vision for determining one or more orientation parameters and especially the second and third Euler angles theta, psi of an elongate object 10 whtion of the one or more orientation parameters and can include asymmetric patterns such as lines, ellipses, rectangles, polygons or the symmetric cases including circles, squares and regular polygons.tion of the one or more orientation parameters and can include asymmetric patterns such as lines, ellipses, rectangles, polygons or the symmetric cases including circles, squares and regular polygons. To produce the patterns the projector 14 can use a scanning arrangement or a structured light optic such as a holographic, diffractive, refractive or reflective element and any combinations thereof.To produce the patterns the projector 14 can use a scanning arrangement or a structured light optic such as a holographic, diffractive, refractive or reflective element and any combinations thereof.The apparatus is suitable for determining the orientation of a jotting implement such as a pen, pencil or stylus.The apparatus is suitable for determining the orientation of a jotting implement such as a pen, pencil or stylus.ose tip 12 is contacting a surface 26 at a contact point 28. The apparatus has a projector 14 mounted on the elongate object 10 for illuminating the surface 26 with a probe radiation 16 in a known patose tip 12 is contacting a surface 26 at a contact point 28. The apparatus has a projector 14 mounted on the elongate object 10 for illuminating the surface 26 with a probe radiation 16 in a known pattern from a first point 18 of view and a detector 20 mounted on the elongate object 10 for detecting a scattered portion 22 of the probe radiation 16 returning from the surface 26 to the elongate objetern from a first point 18 of view and a detector 20 mounted on the elongate object 10 for detecting a scattered portion 22 of the probe radiation 16 returning from the surface 26 to the elongate object 10 from a second point 24 of view. The orientation parameters are determined from a difference between the projected 38 and detected probe radiation 22 such as the difference between the shape of tct 10 from a second point 24 of view. The orientation parameters are determined from a difference between the projected 38 and detected probe radiation 22 such as the difference between the shape of the feature produced by the projected probe radiation 38 and the shape of the feature 22 detected by the detector 20. The pattern 36 of probe radiation 16 is chosen to provide information for determinahe feature produced by the projected probe radiation 38 and the shape of the feature 22 detected by the detector 20. The pattern 36 of probe radiation 16 is chosen to provide information for determina