[vtkusers] RE: vtkusers digest, Vol 1 #1499 - Reply to message 1. small axes (Massimo Ivani)

[Jean-Dominique Barnichon]

Hello,
I have got exactly the same problem, and I have partly found the answer
(there is still
an unsolved question reported at the end of this mail).

Firstly I create 2 renderers :
1) "Renderer" : which is the classical renderer (on which model is
displayed)
2) "RendererAxes" : which is the renderer on which the axes will be
displayed.
	// create the renderer for the axes
	this->RendererAxes = vtkRenderer::New();
	this->RenderWindow->AddRenderer(this->RendererAxes);
	this->RendererAxes->SetViewport(0,0,0.1,0.1);
	this->RendererAxes->InteractiveOff();
Note that this renderer is a portion of the drawing window through the
method SetViewport(0,0,0.1,0.1)
which is exactely what I want, and that the interactor is set inactive with
the method InteractiveOff().

Then I create the axes (code adpated from the book sample) and all the
required stuff
	// create axes
	vtkAxes* axes = vtkAxes::New();
	axes->SetOrigin(0, 0, 0);
	// put tubes around them
	vtkTubeFilter* axesTubes = vtkTubeFilter::New();
	axesTubes->SetInput(axes->GetOutput());
	axesTubes->SetRadius(axes->GetScaleFactor()/25.0);
	axesTubes->SetNumberOfSides(6);
	// Create mapper for tube axes
	vtkPolyDataMapper* axesMapper = vtkPolyDataMapper::New();
	axesMapper->SetInput(axesTubes->GetOutput());
	// create an Actor for axes
	vtkActor* axesActor = vtkActor::New();
	axesActor->SetMapper(axesMapper);

Then, the axesActor is added to the RendererAxes
	// add axes Actor to the Renderer dedicated to Axes
	m_pView->RendererAxes->AddProp(axesActor);

Finally, the camera of RendererAxes is set the same as the main Renderer in
order to show
the same rotations

m_pView->RendererAxes->SetActiveCamera(m_pView->Renderer->GetActiveCamera())
;

All this works, but the main problem is that the RendererAxes is also
affected by changes in the view
distance (i.e. zoom), which is not really intented: you would need your axes
to rotate, but not to change size.
Does anybody has an idea on how this can be done?

Thanks in advance,

Jean-Do
-------------------------------------
Jean-Dominique Barnichon
AmsaTec
24 Porte du Grand Lyon
F-01700 Neyron
E-mail : jdbarnichon at amsatec.com
-------------------------------------

	Message: 1
	From: "Massimo Ivani" <massimo.ivani at mlsw.com>
	To: <vtkusers at public.kitware.com>
	Date: Thu, 2 Jan 2003 13:31:34 +0100
	Subject: [vtkusers] small axes

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	Hello,

	I would like to show a small cube or small axes (always visible) in a =
	corner of vtk windows which rotates when I move camera, so user can =
	better understand 3D model position. How can I do that?

	Thank you

	Dr. Massimo Ivani
	Media Lab Software
	Tel.: +39 0187 517775
	Fax: +39 0187 511833
	massimo.ivani at mlsw.com
	www.mlsw.com <http://www.mlsw.com/>