Shifting pixels in jit.scissors
Hi all,
I'm trying to play some HD content that i made a and play it over 2 beamers. For this i use the jit.scissors but i also have 2 masks to blend the 2 inner sides to line the beamers beter, and have a nice dissolve between A and B. The Masks are 800 x 600 pixels and the dissolve is 100 pixel wide. So the movie has to shift 50 pix in to match up again. And here is the problem.... HOW TO SHIFT THEM?? Try some things with stretching in the jit.movie, but it's now what i want i want a real shift om pixels. Has someone the answer? The patch is included also the 2 masks. Hope someone can help me in right direction :)
Cheers,
Harmen
Here's how you can do an arbitrary overlap. However, for this much
data things might be smoother to use jit..gl.videoplane and texture
offsets for shifting the image and then use your blend masks as a
"jit.gl.texture @lumalpha" texture and do the blending in OpenGL.
wes
Wes, thanx for pointing some things out. I think i almost got what i want by using texture, slab and videoplane, i'm still getting my head around OpenGL.... This is what i came up with. The only problem is that i'm trying to move the 2 texture sepretly, by ginving both textures a name in there object and use the @name in the jit.videoplane to move the position. What i don't get is i give text001 a move command, it moves, but also text002 moves. I'm going on it all day now and get lost. So is there is some one how could give mee a push in the right direction, please let me know
Cheers,
Harmen
Ok, to move the textures separately, you need some kind of offset
parameter for each texture in a shader or two separate videoplanes.
right now, both textures are on the same geometry so they will
definitely move together. Also, the shares in your patch don't have
offset parameters for shifting the 2 inputs independently. As for the
uyvy thing, don't forget that Max is made in San Francisco and
Americans spell color "color" while British folks spell it "colour".
You had @colourmode in your patch which caused an error.
wes
This is what i can come up with (see text file below). But is still don't get it. I can load in a movie. I can load in a mask shape that i make in photoshop, black/whith shape as rgb file. But as soon is I tell the texture to use lumalpha it goes weird the mask image. I tryed converting in to all sort of color spaces, but still it just won't display normal. All i want is a mask to add up ontop of a videofile in OpenGL. How hard could this be? If been going throug the help files like crazzy and scrolling the forum.
A other thing... Were can I get more info about Jitter. I know MAX pretty well for quite some time, but this Jitter is getting to me lately. I just don't understand how some of the other users come up this te solutions you get. I can't come up with that just by reading the Jitter Tutorials, ect. Am I missing something?
If there is some one in The Netherlands willing to give me some more in-depht on Jitter I can help out with beamers (got 5), and loads of other equipment, and locations to show of work.
Cheers,
Harmen
Hi Harmen,
You have a couple of options here (assuming I understand your intentions
correctly). You should have a look at my Jitter Recipes on the Cycling
'74 website. There is one called Alpha Toast that I think will help you
in this instance:
This patch uses matrix-based processing to use a second source as a
luminance-based alpha-channel. Another thing to look at is using
jit.gl.slab with the cc.alphaglue.jxs shader. This provides you with a
lum2alpha mode that will use the luminance of the 2nd input to generate
an alpha (or transparency) mask. See
examples/jitter-examples/render/slab-helpers/color/cc.alphaglue.jxs-help.mxb
for an example of the shader in use.
Hope that helps.
Andrew Benson