[PD] GEM Pix video transparency

[Jonathan Goodwin]

Roman,

Thank you very much! That was spot on! I adapted what you gave me and it's
worked just as I needed it too.

Jonathan


On 12/2/06 15:07, "Roman Haefeli" <reduzierer at yahoo.de> wrote:

> hi jonathan
> 
> i attached an expample, with that you can blend (change transparency)
> between 2 images. just replace [pix_image] with [pix_video] or with
> [pix_movie] (or whatever generates pixes).
> i think the [alpha] adds a fourth channel to the pix-stream. to change the
> transparency (alpha-channel) you need the obj[colorRGB]. i think you could
> do the same with [pix_color], but [colorRGB] computes on the gpu, wich is
> much faster, if you enabled hardware acceleration (opengl). then you need
> [pix_texture] to map the pix-data onto a geo as a texture. also here you
> could achieve the same with [pix_draw] instead of using
> [pix_texure]-[rectangle], but the latter is much cheaper.
> 
> roman
> 
> 
> 
> "Jonathan Goodwin" <jonathan at jgoodwin.co.uk> wrote:
> 
>> I'm trying to figure out the best way to adjust the transparency of
>> pix_video, so that I can overlay a live webcam feed over other videos.
>> 
>> What would people recommend? I've had a little play with the alpha object,
>> but I'm having a bit of trouble understanding the whole threshold
>> arguments
>> thing?!
>> 
>> Jonathan
>>