lstask@gmail.com

Hi there - I'm relatively inexperienced with Jitter, and I was trying to do the following:

I have 6 different images that I need to move around on a white background. The way I've been doing this is based off Tutorial 16 - rendering the images to a named matrix in the appropriate order. However, I have a .js function that determines the order in which the images need to be layered at any given time. As of now, this function spits out a list that I stick, rather arbitrarily, in a [zl join] just to have somewhere for a metro to bang a jit.qball into it regularly.

Aside from this difference, I think I've implemented everything pretty much as the tutorial patch has, but I've noticed a big slowdown and chunky reaction times to the instructions for the images to move around. The relevant part of the patch is included below - I haven't included the .js file but hope that this is enough to diagnose the issue...

Hi there - I'm relatively inexperienced with Jitter, and I was trying to do the following: 

I have 6 different images that I need to move around on a white background.  The way I've been doing this is based off Tutorial 16 - rendering the images to a named matrix in the appropriate order.  However, I have a .js function that determines the order in which the images need to be layered at any given time.  As of now, this function spits out a list that I stick, rather arbitrarily, in a [zl join] just to have somewhere for a metro to bang a jit.qball into it regularly.  

Aside from this difference, I think I've implemented everything pretty much as the tutorial patch has, but I've noticed a big slowdown and chunky reaction times to the instructions for the images to move around.  The relevant part of the patch is included below - I haven't included the .js file but hope that this is enough to diagnose the issue...

multiple-matrix-layer-slowdown

This will be much faster using several instances of 

jit.gl.videoplane. Trying to decompress and composite 6 videos in 

realtime on the CPU will be relatively slow. Almost always faster on 

This will be much faster using several instances of  
jit.gl.videoplane. Trying to decompress and composite 6 videos in  
realtime on the CPU will be relatively slow. Almost always faster on  
the GPU.

Excellent - thanks for that. Definitely snappier.

I'm onto my next task, which is to figure out how to composite several of those images together (via slab, I was thinking...?) but still be able to move them around the screen individually. I've seen a couple instances in the examples of multiple movies being read into a jit.qt.slab, but I need to get at each image intermediately to position them.

I've tried this using both matrices and videoplanes - matrices are still slow (and I couldn't figure out how to erase jit.gl.render properly after moving them around), and the videoplanes seem to require the same name as the videoplane that the jit.qt.slab is feeding into...meaning I can't composite them together, but they rather overlay one another.

Feeling very uncertain that this is the right way to go about it...any help is, as always, greatly appreciated! Thanks!

Excellent - thanks for that.  Definitely snappier.  

I'm onto my next task, which is to figure out how to composite several of those images together (via slab, I was thinking...?) but still be able to move them around the screen individually.  I've seen a couple instances in the examples of multiple movies being read into a jit.qt.slab, but I need to get at each image intermediately to position them.  

I've tried this using both matrices and videoplanes - matrices are still slow (and I couldn't figure out how to erase jit.gl.render properly after moving them around), and the videoplanes seem to require the same name as the videoplane that the jit.qt.slab is feeding into...meaning I can't composite them together, but they rather overlay one another.  

Feeling very uncertain that this is the right way to go about it...any help is, as always, greatly appreciated!  Thanks!

foo is not the name of the jit.gl objects, it's the name of the render

context. Check out the Jitter tutorials on this subject. Try using a

videoplane for each QT movie. Your videoplanes will composite if you

start playing with the blend_mode attribute, e.g., send the following

to the inlet of a videoplane and play with the number boxes:

If your patch still isn't doing what you want it to, think about your

render order. (I like to write it down on a piece of paper.) You want

2. Do Stuff, e.g., draw videoplanes with movies on them, move them

around -- again, check out the GL tutorials to learn how this works --

6. bang jit.gl.render to write the whole thing out to the render context

foo is not the name of the jit.gl objects, it's the name of the render
context.  Check out the Jitter tutorials on this subject.  Try using a
videoplane for each QT movie.  Your videoplanes will composite if you
start playing with the blend_mode attribute, e.g., send the following
to the inlet of a videoplane and play with the number boxes:

If your patch still isn't doing what you want it to, think about your
render order. (I like to write it down on a piece of paper.)  You want
to:

1. erase jit.gl.render
2. Do Stuff, e.g., draw videoplanes with movies on them, move them
around -- again, check out the GL tutorials to learn how this works --
6.  bang jit.gl.render to write the whole thing out to the render context

--
***
http://danwinckler.com
http://share.dj
http://gunshowimprov.com


Thanks Dan - I think I've found a solution, thanks to your nudge towards playing with the blend_mode attribute. This obviates the need for the jit.qt.slab objects in my simple case.

I think there were several other issues in trying to use a videoplane before and after the jit.qt.slab (bad). I was indeed using a videoplane for each movie, as you suggested, but this setup of before and after the slabs was definitely my stumbling block.

Thanks Dan - I think I've found a solution, thanks to your nudge towards playing with the blend_mode attribute.  This obviates the need for the jit.qt.slab objects in my simple case.  

I think there were several other issues in trying to use a videoplane before and after the jit.qt.slab (bad).  I was indeed using a videoplane for each movie, as you suggested, but this setup of before and after the slabs was definitely my stumbling block. 

multiple matrix layer slowdown