<br><br><div class="gmail_quote">On 23 October 2010 22:59, Jim Peterson <span dir="ltr"><<a href="mailto:jimcp@cox.net">jimcp@cox.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Paul Harris wrote:<div class="im"><br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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On 19 October 2010 06:31, Jim Peterson <<a href="mailto:jimcp@cox.net" target="_blank">jimcp@cox.net</a> <mailto:<a href="mailto:jimcp@cox.net" target="_blank">jimcp@cox.net</a>>> wrote:<br>
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Paul Harris wrote:<br>
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My models do not have any particular handedness, ...<br>
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all 3D models have a "handedness" Right handed says the positive<br>
Y axis is a 90degree rotation counter clockwise from the positive<br>
X axis, the positive Z axis is 90 degrees counter clockwise from<br>
the X/Y plane along the Y positive axis. "Left handed" is the<br>
same rule with "counter clockwise" replaced with "clockwise". you<br>
trasnform between the two by either reversing the direction of Z<br>
or exchanging X and Y.<br>
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Ok well in that case, some of the models I view are right-handed, some are left-handed. I need to support both.<br>
I might have no choice but to insist on whatever VTK is happy with.<br>
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Paul,<br>
the essential problem here is the input polydata (at whatever point that exists is the manifestation in the current world coordinate system of the objects represented by the numbers generated by the original coordinate system. The vtkPolyDataFilter is designed to adjust all model related aspects of the poly data, it needs to be applied to the poly data, not the actor. My reasoning is multiple input objects, some right handed, some left handed, may be processed as inputs to the same mapper or actor. So in my Java reinterpretation of your program, the dark surface problem is resolved by applying the vtkPolydata filter to the output of the cone source, and using the output of the filter in the mapper.... as:<br>
</blockquote><div><br><br>So you are saying that whatever coordinates that are passed to actors must already be in VTK's world coordinate system, which is fixed. If I need to (eg) flip the entire scene (all of the models), I can't adjust the world coordinate system, instead I must adjust all of the models instead (eg via vtkPolyDataFilter).<br>
<br>I was hoping that I could adjust the world coordinate system - you can do it at the camera (eg adding a Yaw for 3d glasses), but that trick doesn't work if you have to flip one of the axes due to lighting problems.<br>
<br>thanks<br>Paul<br><br></div></div>