about transparency

• To: visad-list <visad-list@xxxxxxxxxxxxx>
• Subject: about transparency
• From: Zhaopeng Lei <zlei@xxxxxxxxxxxxxxx>
• Date: Mon, 15 Apr 2002 15:57:31 -0400 (EDT)

Hi there
I am using RGBA in volume rendering(dataset 109*256*256). My expected
effect is to let pixels where data value equals 0 to be complete transparent.
However, the result looks like a cube filled with black ink.
Could you please tell me what's wrong with my code? Thanks a lot.

    int tableLength = 10;
    float[][] myColorTable = new float[4][tableLength];
    for(int i=0;i<tableLength;i++){
      myColorTable[0][i]=(float)(float)i/((float)tableLength-1.0f);//red
      myColorTable[1][i]=(float)(float)i/((float)tableLength-1.0f);//green
      myColorTable[2][i]=(float)(float)i/((float)tableLength-1.0f);//blue
      myColorTable[3][i]=(float)(float)i/((float)tableLength-1.0f);//alpha
    }

    // Force top of table to be white
    myColorTable[0][9]=1.0f;
    myColorTable[1][9]=1.0f;
    myColorTable[2][9]=1.0f;
    myColorTable[3][9]=1.0f;

    // Get the ColorControl from the altitude RGB map
    ColorAlphaControl colCont = (ColorAlphaControl)
    valueRGBMap.getControl();
    // Set the table
    colCont.setTable(myColorTable );



- Zhaopeng :-)


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• Follow-Ups:
  • Re: about transparency
    • From: Bill Hibbard