Im trying to overlay some text on a gl video plane, but what results is the text within small boxes.

I think there must be a simple way to solve this, but suggestions from the past lists dont work or I might be missing something.

using osx 10.4.6 and Max/Msp 4.5.7 Jitter 1.5.2

Im trying to overlay some text on a gl video plane, but what results is the text within small boxes. 

jit-gl-text2d-on-jit-gl-videoplane

On Jun 2, 2006, at 4:01 AM, darcysays wrote:

> Im trying to overlay some text on a gl video plane, but what 

> results is the text within small boxes.

> I think there must be a simple way to solve this, but suggestions 

> from the past lists dont work or I might be missing something.

Your problem is as follows: in automatic mode there is currently no 

way to enforce the sequence of object rendering. In your patch your 

text is rendered first, and then the videoplane. This obscures the 

text in the absence of depth testing (default off for jit.gl.text2d).

If depth_enable is *on*, however, then the videoplane will not render 

anywhere the text is closer to the camera (for the entire 

quadrilateral which has been rendered for each glyph, as the depth 

buffer is written to based on the geometry, not the glyph's alpha 

The correct way to do this in the current version of Jitter is to 

disable automatic mode and then explicitly render the text last, 

In the next version of Jitter there are two new attributes which 

would be of use in these types of scenarios:

- @layer : in automatic mode object rendering order is 

sorted from low to high based on layer number, default 0. (note: 

objects in the same layer are not guaranteed any specific rendering 

- @depth_clear : before rendering object, clear the depth 

buffer (useful for having 3D layers which need depth testing internal 

to rendering it's geometry--e.g. a sphere--but wish to override the 

depth buffer for all previously rendered objects)

jit.gl.render drawclients message also has a new optional layer 

number argument for only drawing objects in a specifc layer.

Coming soon to a theater near you (no please don't ask for dates).

> Im trying to overlay some text on a gl video plane, but what  
> results is the text within small boxes.
> I think there must be a simple way to solve this, but suggestions  
> from the past lists dont work or I might be missing something.

Your problem is as follows: in automatic mode there is currently no  
way to enforce the sequence of object rendering. In your patch your  
text is rendered first, and then the videoplane. This obscures the  
text in the absence of depth testing (default off for jit.gl.text2d).

If depth_enable is *on*, however, then the videoplane will not render  
anywhere the text is closer to the camera (for the entire  
quadrilateral which has been rendered for each glyph, as the depth  
buffer is written to based on the geometry, not the glyph's alpha  
channel).

The correct way to do this in the current version of Jitter is to  
disable automatic mode and then explicitly render the text last,  
without depth testing. Example is below.

In the next version of Jitter there are two new attributes which  
would be of use in these types of scenarios:

- @layer  : in automatic mode object rendering order is  
sorted from low to high based on layer number, default 0. (note:  
objects in the same layer are not guaranteed any specific rendering  
order)
- @depth_clear : before rendering object, clear the depth  
buffer (useful for having 3D layers which need depth testing internal  
to rendering it's geometry--e.g. a sphere--but wish to override the  
depth buffer for all previously rendered objects)

jit.gl.render drawclients message also has a new optional layer  
number argument for only drawing objects in a specifc layer.

However I am finding that this now causes some video break up/artifacts. It is noticable when there are moving objects within the footage. It happens on both jit.qt.movie and jit.qt.grab on that patch you sent.

Unfortunaetly screen captures I have taken don't show the problem, but can you or anyone else reproduce it? Does the video in that patch play smoothly without artifacts?

ATI Mobility Radeon 9000 (AGP 4X) / 64 MB of DDR SDRAM

OSX 10.4.6 and Max/Msp 4.5.7 Jitter 1.5.2

PowerBook G4/1.0GHz 
1GIG RAM
ATI Mobility Radeon 9000 (AGP 4X) / 64 MB of DDR SDRAM
OSX 10.4.6 and Max/Msp 4.5.7 Jitter 1.5.2


I can't reproduce this problem on the development version I'm using 

at the moment. However, if you send jit.glvideoplane the message: 

"sendtexture mode static" does the problem disappear?

Otherwise, could you be more specific about what artifacts you are 

seeing? Is it just from interlaced movies, or input devices?

If you're unfamiliar with how to tell if it is simply from interlaced 

FWIW, this page seems like a good resource for people interested in a 

variety of video issues. Just came across it for the first time 

I can't reproduce this problem on the development version I'm using  
at the moment. However, if you send jit.glvideoplane the message:  
"sendtexture mode static" does the problem disappear?

Otherwise, could you be more specific about what artifacts you are  
seeing? Is it just from interlaced movies, or input devices?

If you're unfamiliar with how to tell if it is simply from interlaced  
source, please read the following:

FWIW, this page seems like a good resource for people interested in a  
variety of video issues. Just came across it for the first time  
today. Will add to our resource guide.

another excellent explanation/solution for deinterlacing (and much more)

another excellent explanation/solution for deinterlacing (and much more)
http://www.100fps.com/


Just incase your interested this was the distortion I was getting: 

Quite a bit different from the normal interlacing drama.

Just incase your interested this was the distortion I was getting: http://darcy.co.nz/artifacts.mov
Quite a bit different from the normal interlacing drama.

jit.gl.text2d On jit.gl.videoplane