GeClipMap alpha [SOLVED]

On 19/11/2016 at 11:13, xxxxxxxx wrote:

Hi I would like to import tiff with alpha into a Geclip and still got this alpha but I didn't sucess.
Thanks in advance here is a little code for testing.

import c4d
def main() :
        path = "C:\\Program Files\\MAXON\\CINEMA 4D R17\\plugins\\MyPlugin\\res\\add2.tif"
        #On init un bitmap ave l'image
        temp = c4d.bitmaps.BaseBitmap()
        if temp.InitWith(path)[0] != c4d.IMAGERESULT_OK:
            return False
        size = temp.GetBw()
        alpha = temp.GetInternalChannel()
        #Initialize GeClipMap
        cm = c4d.bitmaps.GeClipMap()
	#Some test for rewritting alpha
        if alpha:
            for y in xrange(size) :
                for x in xrange(size) :
                    a = temp.GetAlphaPixel(alpha,x,y)
                    r,g,b = temp.GetPixel(x,y)
                    cm.SetPixelRGBA(x, y, r, g, b,a)    
        #draw a square
        cm.SetDrawMode(c4d.GE_CM_DRAWMODE_BLEND, 255)
        cm.SetColor(150, 150, 150, 150)
        size_pic = cm.GetBw()
        height_pic = cm.GetBh()
        cm.FillRect(0, height_pic - (size/6), size_pic,height_pic )
        #Get bitmap
        bmp = cm.GetBitmap().GetClone()
if __name__=='__main__':

On 21/11/2016 at 03:00, xxxxxxxx wrote:


the BaseBitmap returned by GetBitmap() does not include the alpha channel (see documentation). Also the Picture Viewer would not display the alpha channel.

So as far as I can see you have to copy the alpha channel manually.

# clone bitmap  
bitmap = clipMap.GetBitmap().GetClone()  
# add alpha channel  
alphaChannel = bitmap.AddChannel(True, False)  
# copy alpha  
for x in xrange(clipMapWidth) :  
  for y in xrange(clipMapHeight) :  
      r,g,b,a = clipMap.GetPixelRGBA(x,y)  
      bitmap.SetAlphaPixel(alphaChannel, x, y, a)  
# save bitmap with alpha  
saveImageFile =,title="Save as PNG")  
if saveImageFile is not None:  
  bitmap.Save(name = saveImageFile,format = c4d.FILTER_PNG,data = None, savebits =c4d.SAVEBIT_ALPHA)   

best wishes,

On 21/11/2016 at 05:35, xxxxxxxx wrote:

Thanks you was a missunderstand from me.
I thinked alpha was not copied into the GeClip.

Anyway thanks you now all is working as excepted ! 🙂