[PD] GEM: help with alpha settings

[IOhannes zmoelnig]

 >  --- bbogart at ryerson.ca wrote:
 >> Don't use pix_alpha,
 >> but put colorRGB and alpha
 >>objects at the end of the chain. The last inlet to
 >>colorRGB is the alpha of the object from 0-1.

arm pdlist wrote:
> I forgot to mention that i use pix_texture2 and
> rectangle to show the pic. 
never mind
 > Do you mean i have to put
> rectangle, then colorRGB and alpha (being these 2 the
> last objects on the chain?

no.
as you might have noticed, in Gem basic modifiers (like [rotate], 
[color] or [alpha]) apply to all openGL-objects ("Geos", like 
[rectangle] or [sphere]) that are "below" them.
thus "colorRGB and alpha (being these 2 the last objects on the chain)" 
will have no effect at all.
it should look like

[pix_film superdooper.avi]
|
[pix_texture2]
|
[colorRGB]
|
[alpha]
|
[rectangle 4 3]

the last inlet of [colorRGB] is for alpha (as ben has already said) and 
sets the colour for the rectangle (this has nothing to do with the 
texture-data). Since this can be done by hw-accelerated gfx-cards, it 
might be very fast (setting the alpha-channel of the image-data would be 
slow)
[alpha] enables alpha-blending (otherwise the alpha-channel would be 
ignored)

mfg.a.dsr
IOhannes