<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial,helvetica,sans-serif;font-size:10pt"><div>VTKEdge is a good extension to VTK, but I can't use it in my project because VTKEdge is released under GPL and I can't release my software under GPL.<br></div><div style="font-family: arial,helvetica,sans-serif; font-size: 10pt;"><br><div style="font-family: arial,helvetica,sans-serif; font-size: 13px;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">Da:</span></b> Karthik Krishnan <karthik.krishnan@kitware.com><br><b><span style="font-weight: bold;">A:</span></b> AGPX <agpxnet@yahoo.it><br><b><span style="font-weight: bold;">Cc:</span></b> vtkusers@vtk.org<br><b><span style="font-weight: bold;">Inviato:</span></b> Venerdì 31 ottobre 2008, 14:36:02<br><b><span style="font-weight: bold;">Oggetto:</span></b> Re: [vtkusers] Hardware Volume Rendering
Quality<br></font><br>VTKEdge supports GPU ray casting. It uses floaring point textures. So<br>your quantization artefacts will be far less. It also handles NPOT<br>textures (assuming<br>of course that your graphics card supports floaring point textures and NPOT<br>textures)<br><br>See vtkedge.org<br><br>On Fri, Oct 31, 2008 at 3:00 AM, AGPX <<a ymailto="mailto:agpxnet@yahoo.it" href="mailto:agpxnet@yahoo.it">agpxnet@yahoo.it</a>> wrote:<br>> Hello,<br>><br>> I'm quite new to VTK, but looking at vtkOpenGLVolumeTextureMapper3D.cxx, it<br>> seem to me that (probably for memory reason), 16 bit volumes are always<br>> reduced to 8 bit. I'm very disappointed about this limit. A volume with 2560<br>> different level, will be reduced to only 255! I wish to know: there are some<br>> planning to support 16 bit hardware volume rendering in future release? In<br>> addition, take a look at this code:<br>><br>> int
vtkOpenGLVolumeTextureMapper3D::IsTextureSizeSupported( int size[3] )<br>> {<br>> if ( this->GetInput()->GetNumberOfScalarComponents() < 4 )<br>> {<br>> if ( size[0]*size[1]*size[2] > 128*256*256 )<br>> {<br>> return 0;<br>> }<br>> vtkgl::TexImage3D(vtkgl::PROXY_TEXTURE_3D, 0, GL_RGBA8, size[0]*2,<br>> size[1]*2, size[2], 0, GL_RGBA, GL_UNSIGNED_BYTE,<br>> this->Volume2 );<br>> ...<br>> }<br>> Why the width and height of the texture are doubled in the call to the<br>> TexImage3D? How much video-memory a volume (with less than 4 scalar<br>> components) need? (size[0] * 2) * (size[1] * 2) * size[2] * 4 ? That is,<br>> 16
bytes per voxel?<br>> In addition, looking at UpdateVolumes. From the function<br>> vtkVolumeTextureMapper3D::UpdateVolumes, I see the following code:<br>><br>> ...<br>><br>> int neededSize = powerOfTwoDim[0] * powerOfTwoDim[1] * powerOfTwoDim[2];<br>><br>> ...<br>><br>> switch (components)<br>> {<br>> case 1:<br>> this->Volume1 = new unsigned char [2*neededSize];<br>> this->Volume2 = new unsigned char [3*neededSize];<br>> this->Volume3 = NULL;<br>> break;<br>> ...<br>> }<br>><br>><br>><br>> That is, for one component scalar, a volume need 5 times the neededSize<br>> (i.e. the dimesion of the volume, nearest to the power of two) bytes of<br>> system memory. Is this correct?<br>><br>><br>><br>> Thanks in advance,<br>><br>> -
AGPX<br>> ________________________________<br>> Scopri la community di Io fotografo e video<br>> Il nuovo corso di Gazzetta dello sport per diventare veri fotografi!<br>> _______________________________________________<br>> This is the private VTK discussion list.<br>> Please keep messages on-topic. Check the FAQ at:<br>> <a href="http://www.vtk.org/Wiki/VTK_FAQ" target="_blank">http://www.vtk.org/Wiki/VTK_FAQ</a><br>> Follow this link to subscribe/unsubscribe:<br>> <a href="http://www.vtk.org/mailman/listinfo/vtkusers" target="_blank">http://www.vtk.org/mailman/listinfo/vtkusers</a><br>><br>><br><br><br><br>-- <br>Karthik Krishnan<br>R&D Engineer,<br>Kitware Inc.<br>Ph: 518 371 3971 x119<br>Fax: 518 371 3971<br></div></div></div><br>
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