[vtkusers] Looking for the perfect scalarRange...
rafael possani
gentefinabr at hotmail.com
Fri Sep 7 09:24:11 EDT 2007
Hi Geoframer,
That was like y said, I just put a colorbar and I understood how a lookuptable works. Now I seeing, on the screen, my project almost complete :)
Thanks a lot and have a nice weekend.
bye bye
Rafael.
Date: Fri, 7 Sep 2007 12:48:40 +0200
From: geoframer at gmail.com
To: gentefinabr at hotmail.com
Subject: Re: [vtkusers] Looking for the perfect scalarRange...
CC: vtkusers at vtk.org
Hi Rafael,
The fact that you only get one color in this case blue probably means that the range of your scalars (the ones you use for color are all in the high range of your lookuptable or higher then 1. The lookuptable starts at 0 (red) and up to the 1 (blue) and is in your case setup into 9344 intervals. I don't know exactly how the make up of your scalars is but an easy test would be to set a few to 0 and see if you then get red and blue colors. If yes then the pipeline works correctly but the scalarvalues are to close to another (and probaby to high) and you need some kind of multiplier/divider to pull them apart.
In general a trick i used when i was first trying to grasp how lookuptables work is to add a colorbar based on the lookup table. This colorbar will show you the colors as they are mapped through your lookuptable. Just adding this would quicky show if your lookuptable contains only one color and hence is faulty or in fact multiple colors which would imply that your scalars need some work.
#create a colorbar
colorbar = vtk.vtkScalarBarActor()
colorbar.SetLookupTable(lookupTable)
colorbar.SetWidth(0.05)
colorbar.SetPosition(0.95, 0.1)
colorbar.SetLabelFormat("%.3g")
colorbar.PickableOff
()
colorbar.VisibilityOn()
ren.AddActor(colorbar)
Regards and hope this helps some - Geoframer
On 9/6/07, rafael possani <
gentefinabr at hotmail.com> wrote:
Hi Geoframer, first of all , thanks a lot for the reply, and well I have tested a lookuptable too, but without luck, I think that I mistaken some method, then I eraser my lookuptable and I writed another one like yours. And I still cant see the colors, only one cor, generally blue. Then I will post my program better to see if you may help me, one more time :)
I have 9344 points(values) into a vtkdoublearray, each one with a value in scientific notation(like around 20 kinds of combinations), for example, 3.5E-5, 1.0E-5, 1.0E-5 and 7.7E-6, my bigger number is 7.7E-6, and my lesser is
0.0, then I tried it in my lookuptable:
lookupTable = vtk.vtkLookupTable()
lookupTable .SetNumberOfColors(9344);
lookupTable .SetTableRange(0,7.7E-6);
lookupTable .ForceBuild();
After that I add into my mapper like y said:
conjunto.SetLookupTable(lookupTable );
And in my vtkImageMapToColors:
oIMTC1 = vtk.vtkImageMapToColors();
oIMTC1.SetLookupTable(lookupTable );
But, as my mapper as my vtkImageViewer still be with just one color. Do you suggest some change?
Thanks, again.
Rafael.
Date: Thu, 6 Sep 2007 13:10:59 +0200
From: geoframer at gmail.com
To:
gentefinabr at hotmail.com
Subject: Re: [vtkusers] Looking for the perfect scalarRange...
CC: vtkusers at vtk.org
Hi Rafael,
I think you're missing a lookup table. Your mapper needs a lookuptable to see what scalar is translated into which color.
I suggest creating a lookuptable and adding the lookuptable to the mapper.
lookupTable = vtk.vtkLookupTable()
lookupTable.SetNumberOfColors(numberofscalars)
lookupTable.SetTableRange(0,1)
lookupTable.ForceBuild()
conjuto..SetLookupTable(lookupTable)
You'll probably need to take a closer look at lookup tables as i use a discrete number of colors (hence the SetNumberOfColors), no idea what kind of table you need.
Regards - Geoframer
On 9/6/07, rafael possani <gentefinabr at hotmail.com
> wrote:
Hi vtk-users, I am with a problem. I am reading xy point into a vtkStructuredPoints and I would like to save like a image, but I cant... my vtkRenderWindow shows ok, but my image dont have colors and I know why, I need to set the scalars range into the vtkStructuredPoints but I dont know what method to use, that a part of my code:
vtkStructuredPoints points = new vtkStructuredPoints();
points.SetDimensions( 128, 73, 1);
points.SetOrigin( 0.0, 0.0, 0.0 );
points.SetSpacing( 1.0, 1.0, 1.0 );
points.SetScalarTypeToUnsignedChar
();
points.SetNumberOfScalarComponents(id);
points.GetPointData().SetScalars( scalars ); // <--- Doesn´t work :/ with that my image only be red
the scalars vector are double in Scientific notation I dont know if its bad.
I have been trying all possible methods but I hadn´t success.
my mapper renders ok:
vtkDataSetMapper conjunto = new vtkDataSetMapper();
conjunto.SetInput(points);
conjunto.SetScalarRange
(points.GetScalarRange()); <---- But it works here
I´m thinking that a need a method like SetScalarRange from my mapper to use before in my vtkStructuredPoints.
besides, I am using vtkImageMapToColors to convert my structured points into a image. I also can post my entire code, but I made the same like this link, without the beginning because I generated my points :)
http://public.kitware.com/pipermail/vtkusers/2005-December/083147.html
Well, someone suggest me a method for my vtkStructuredPoints? thanks in advanced.
Receba GRÁTIS as mensagens do Messenger no seu celular quando você estiver offline. Conheça o MSN Mobile!
Cadastre-se já!
_______________________________________________
This is the private VTK discussion list.
Please keep messages on-topic. Check the FAQ at:
http://www.vtk.org/Wiki/VTK_FAQ
Follow this link to subscribe/unsubscribe:
http://www.vtk.org/mailman/listinfo/vtkusers
Receba GRÁTIS as últimas novidades do esporte direto no seu Messenger!
Assine já!
_________________________________________________________________
Receba GRÁTIS as últimas novidades do esporte direto no seu Messenger!
http://signup.alerts.live.com/alerts/login.do?PINID=37485679&returnURL=http://www.nivea.com.br
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20070907/4068b92f/attachment.htm>
More information about the vtkusers
mailing list