<br><br><div class="gmail_quote">On Sun, Jun 28, 2009 at 7:59 AM, <span dir="ltr"><<a href="mailto:enjoywm@cs.wm.edu">enjoywm@cs.wm.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi,<br>
I want to render a color volume with 4 components: RGBA.<br>
I want to use component alpha instead of opacity mapping function to<br>
control the opacity. Can I do this?<br>
<br>
Thanks for help.<br>
<br>
Yixun<br>
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</blockquote></div><br><div><br></div><div>This Was my qeuestion about a week age and I used this Soloution:</div><div>Filling an Image with 4 component r g b and alpha (value between 0 255)</div><div><br></div><div><div>
<br></div><div>vtkImageData* pImage=vtkImageData::New();</div><div>pImage->SetDimensions(512,512,1);<br></div><div>pImage->SetScalarTypeToUnsignedChar();<br></div><div>pImage->SetNumberOfScalarComponents(4);<br>
</div><div>pImage->AllocateScalars();</div><div><br></div><div>and </div><div>a For filling it a code like this</div><div><div><span class="Apple-tab-span" style="white-space:pre"> </span>ptr=(unsigned char*)pImage->GetScalarPointer();</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span>while (i<count)</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>{</div></div></div><blockquote class="webkit-indent-blockquote" style="margin: 0 0 0 40px; border: none; padding: 0px;">
<span class="Apple-tab-span" style="white-space:pre"> </span>*ptr=0;ptr++;//red<br> *ptr=120; ptr++; //green<br> *ptr=0;ptr++;//blue<br> *ptr=i%255;ptr++;//alpha<br><br></blockquote><div><div><div>
<span class="Apple-tab-span" style="white-space:pre"> </span> </div><div><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div>
<br></div></div><div><br></div><div>and I Used it as Texture for a plane</div><div>vtkTexture* pTex=vtkTexture::New();<br></div><div><div>pTex->SetInput(pImage);<span class="Apple-tab-span" style="white-space:pre"> </span></div>
<div><br></div></div></div>