<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi,<div> The solution to this problem is to use the Tcl eval command, as follows</div><div><br></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><span class="Apple-tab-span" style="white-space:pre"> </span>eval arrowGlyphPoints InsertNextPoint [planeSource GetNormal]</div></div><div><br></div><div>This will expand the pointer to the normal co-ordinates, to a list, so that InsertNextPoint will get the x, y and z coordinate inputs.</div><div><br></div><div>Other alternative solutions to this problem can be found here: <a href="http://www.nabble.com/simple-question-about-Tcl-and-VTK-ts6746384.html%23a6746384">Nabble - VTK - Users - simple question about Tcl and VTK</a></div><div><br></div><div>Ok, so I got that fixed, but now I have a problem that I cannot explain. The output of the program is still wrong. The surface normal vector should be pointing perpendicular to the plane surface </div><div><br></div><div><img height="547" width="559" apple-width="yes" apple-height="yes" src="cid:985A3C78-87C1-42F6-9496-C678D436218B@du.ae"></div><div>How can I fix this? The arrow should be pointing upwards, from the plane surface. </div><div><br></div><div>Note that at some point, I decided to simplify the problem using a plane surface, try to solve the display of the surface normal first, before progressing on to display the surface normal glyph for a triangle cell.</div><div><br></div><div><br></div><div>Best regards,</div><div><br></div><div>Elvis Dowson</div><div><br><div><div>On Oct 8, 2008, at 11:02 AM, Elvis Dowson wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi,<div> I'm just trying to breakdown the problem. I'm just stuck at one point below. Could someone help? </div><div><br></div><div><font class="Apple-style-span" face="Monaco" size="2"><span class="Apple-style-span" style="font-size: 10px;">arrowGlyphPoints InsertNextPoint [planeSource GetNormal]</span></font></div><div><br></div><div>I have a plane source and I want to pass the plane normal to an arrow glyph. I'm using vtkPoints to represent the location of the arrow glyph. I can't seem to get the correct data type to be passed from vtkPlanceSource::GetNormal() to vtkPoints::InsertNextPoint() in TCL. I get the error message, Object named: arrowGlyphPoints, could not find requested method: InsertNextPoint</div><div>or the method was called with incorrect arguments.</div><div><br></div><div>How can I fix the call to the above method in TCL?</div><div><br></div><div>Here are the method declarations. </div><div><br></div><div><font class="Apple-style-span" face="Monaco" size="2"><span class="Apple-style-span" style="font-size: 10px;">vtkPoints::InsertPoints(const double x[3]) </span></font></div><div><font class="Apple-style-span" face="Monaco" size="2"><span class="Apple-style-span" style="font-size: 10px;"><br></span></font></div><div><font class="Apple-style-span" face="Monaco" size="2"><span class="Apple-style-span" style="font-size: 10px;">virtual double* vtkPlaneSource::GetNormal()</span></font></div><div><font class="Apple-style-span" face="Monaco" size="2"><span class="Apple-style-span" style="font-size: 10px;">virtual void vtkPlaneSource::GetNormal(double data[3]) </span></font></div><div><br></div><div>Question: How can I pass data[3] or double * returned by vtkPlaneSource::GetNormal() into vtkPoints::InsertNextPoint() ? </div><div><br></div><div>Best regards,</div><div><br></div><div>Elvis Dowson</div><div><br></div><div><br></div></div></blockquote></div></div></body></html>