<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:12pt"><div><span class="tab">Hello,</span></div><div><br><span class="tab"></span></div><div><span class="tab">Here's my problem. I use vtk 5.8.0 on a windows XP platform with 3GB of RAM (it is an application using vtk and Qt). I have a geometry </span><span id="result_box" class="short_text" lang="en"><span class="hps">which is composed of about 2 000 000 hexadrons cells. My geometry is composed of about 20 blocks.</span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">Now, I want to transform my 20 unstructuredGrid blocks (in a vtkMultiBlockDataSet) in one polydata or unstructuredGrid. </span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">First, I have try the
vtkMergeCells in order to have 1 vtkUnstructuredGrid. I have the following error: <br></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">vtkDataArrayTemplate.cxx l 359 Unable to allocate 35,793,215 Elements of... (I don't have the end of the message). The number (35,793,...) is not always the same.</span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">Now, I have decided to use the vtkAppendFilter. For that I use the following code :</span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps"><br></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">vtkAppendPolyData* append = vtkAppendPolyData::New();<br><br>for(unsigned int i = 0; i < mbds->GetNumberOfBlocks();
++i)<br> {<br> vtkDataSetSurfaceFilter* dssf = vtkDataSetSurfaceFilter::New();<br> dssf->PassThroughCellIdsOn();<br> dssf->PassThroughPointIdsOn();<br><br> dssf->SetInput( ptr_mbds->GetBlock(i) );<br> dssf->Update();<br><br> append->AddInput( dssf->GetOutput());<br><br> dssf->Delete();<br> }</span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span><span id="result_box" class="short_text" lang="en"><span class="hps"> append->Update();</span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box"
class="short_text" lang="en"><span class="hps">With this code, I have the same error. It occurs at line269 of vtkAppendPolyData.cxx -> newStrips->Allocate(numCells*4); with numCells = 2251994</span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">I don't know why there is this multiplication *4 since we have the exact number of cells. May be the process will create more cells than it exists.</span></span></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">Moreover, both method are very time consuming.<br></span></span></div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span><div><span id="result_box" class="short_text" lang="en"><span
class="hps">So, can someone tell me what 's wrong with my methods and what can I do to display my geometry ?</span></span></div><div><br></div><div><br><span id="result_box" class="short_text" lang="en"><span class="hps"></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps">Thank you.<br></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class="hps"><br></span></span></div></div></body></html>