[vtkusers] How to determine the number of triangles or points rendered by mapper

[Paul McIntosh]

The amount of triangles rendered depends on what is needed to make a nice picture. For example, if you try and select a surface through ParaView and then calculate the area, if the triangles are very fine, your result will be wrong as a large percentage are not rendered. This is because the select function is getting info from the GPU. You can test this by selecting from a distance, extracting the selection and then zoom in.

To calculate the area of a mesh I created a little util which counts the rendered pixels and this does the job accurate enough for me (calculating the frontal area of a vehicle)

https://github.com/internetscooter/Vespa-Labs/tree/master/VespaCFD/CalculateFrontalArea

https://github.com/internetscooter/Vespa-Labs/blob/master/VespaCFD/CalculateFrontalArea/CalculateFrontalArea_README.docx

Not sure if it helps.

Paul

----- Original Message -----
> From: "Aashish Chaudhary" <aashish.chaudhary at kitware.com>
> To: "jamsoft" <jamsoft at seznam.cz>
> Cc: "vtkusers" <vtkusers at vtk.org>
> Sent: Friday, 20 June, 2014 2:24:38 PM
> Subject: Re: [vtkusers] How to determine the number of triangles or points rendered by mapper
> 
> 
> 
> 
> 
> 
> On Thu, Jun 19, 2014 at 5:20 PM, jamsoft < jamsoft at seznam.cz > wrote:
> 
> 
> Hi all,
> I'm using three types of mappers (and HW - CPU, GPU & VolumePro 1000)
> to
> render the same volumetric data. The image is rendered well
> 
> 
> What I need now is to determine the number of rendered triangles or
> points
> for each of these devices but I have no idea how to do that...
> 
> 
> 
> I am not sure if I understood your question here. Do you mean voxels
> may be?
> 
> 
> I'm using the VTK 5.10.
> 
> Every help will be highly appreciated,
> 
> 
> 
> - Aashish
> 
> 
> Thank you in advance,
> 
> JaM
> 
> 
> 
> --
> View this message in context:
> http://vtk.1045678.n5.nabble.com/How-to-determine-the-number-of-triangles-or-points-rendered-by-mapper-tp5727567.html
> Sent from the VTK - Users mailing list archive at Nabble.com.
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/vtkusers
> 
> 
> 
> 
> --
> 
> | Aashish Chaudhary
> | Technical Leader
> | Kitware Inc.
> 
> | http://www.kitware.com/company/team/chaudhary.html
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/vtkusers
> 

-- 
Dr Paul McIntosh
  Senior HPC Consultant, Technical Lead,
    Multi-modal Australian ScienceS Imaging and Visualisation Environment (www.massive.org.au)
       Monash University, Ph: 9902 0439 Mob: 0434 524935