Cycling 74 » Topic: jit.gl.render repeating context in imagebuffer

jit.gl.render repeating context in imagebuffer

Thijs Koerselman — Tue, 17 Jan 2006 22:20:42 +0000

I’d like to run the following sequence using jit.gl.render:

- erase imagebuffer
- set render parameters (like camera)
- render context to imagebuffer
- change render parameters
- render context to imagebuffer (adding up)
- output frame

I can do stuff like this with other gl object using @automatic 0, but I
can’t find a way to render a complete context like this. It looks like
writing to the imagebuffer always generates a frame. Is this even possible?

Thijs

Re: jit.gl.render repeating context in imagebuffer

wallace winfrey — Tue, 17 Jan 2006 22:27:02 +0000

This topic is more appropriate for the Jitter list/forum. Moving it there now.

Re: jit.gl.render repeating context in imagebuffer

Wesley Smith — Tue, 17 Jan 2006 22:36:56 +0000

I’m not sure that this is entirely possible until whole scene render to texture is properly supported. For now, you can try doing the following:

erase render
draw objects
bang render
draw objects with additive blend mode
bang render

Notice the second pass has no erase. Good luck!

wes

Re: jit.gl.render repeating context in imagebuffer

jasch — Tue, 17 Jan 2006 22:41:56 +0000

yes, thats fine for the fori,
but shouldn’t these messages still show up on the main-maxmsp-list?

Re: jit.gl.render repeating context in imagebuffer

vade — Tue, 17 Jan 2006 22:45:33 +0000

Aha -

“I’m not sure that this is entirely possible until whole scene render
to texture is properly supported. For now, you can try doing the
following”

I had asked a question earlier regarding this. I noticed the @capture
only allowed for a ‘One GL object’ to ‘One Texture’ mapping. I
couldnt have two jit.gl.whatevers objects both with ‘@capture
destination’ and get jitter to render both objects to the texture
destination. This makes sense I suppose.

I am getting errors with jit.gl.render ‘to_texture destination’
method (which I was trying to substitute for @capture). Is this still
supported, and does it work to capture the whole render context to a
texture on the GPU? Is this possible at all in any way under jitter?

Sorry if im being annoying with this question (and for possibly
thread hijacking), but it is functionality I would love to see, and
if it does work, I cant get it to work, and If this isnt possible, I
humbly request this as a feature updated to the next jitter.

Thanks a lot.

BTW: the to_texture error I get is :

warning: method screen_grab called on invalid object

v a d e //

http://www.vade.info
abstrakt.vade.info

Re: jit.gl.render repeating context in imagebuffer

Thijs Koerselman — Tue, 17 Jan 2006 22:54:50 +0000

I haven’t quite followed the whole forum list change thing, but I subscribed
to the jitter list so I guess it’ll be alright. I’ll post my jitter
questions to the jitter list from now on. I’m hoping that most others jitter
users read that list, because if there are more people like me, they don’t
feel like hanging around on the forum.

Re: jit.gl.render repeating context in imagebuffer

jasch — Tue, 17 Jan 2006 23:04:18 +0000

well, there’s not much choice really, if you want to/need to keep up
with several topics, you need to subscribe to several lists.
the unpleasant part is not being told about it.

/*j

Re: jit.gl.render repeating context in imagebuffer

Thijs Koerselman — Tue, 17 Jan 2006 23:26:32 +0000

I think it all has to do with the fact that jitter doesn’t support sharing textures amongs different render contexts. It has come up a few times before and Joshua wrote they’re working on it.

I already tried the multiple bang method without the erase, but this didn’t seem to work, and also doubles the framerate, which isn’t something I can use. I guess I’ll just wait for the next jitter release.

Re: jit.gl.render repeating context in imagebuffer

Wesley Smith — Tue, 17 Jan 2006 23:31:22 +0000

I don’t think it has to do with sharing between contexts, but more to
do with the lack of render to texture or pbuffers.

wes

Re: jit.gl.render repeating context in imagebuffer

vade — Tue, 17 Jan 2006 23:32:41 +0000

Hm. Thanks for the info. I seemed to have missed this.

Are you able to get jit.gl.render ‘to_texture’ to work? I seem to be
missing something wrt setting it up properly.

Any info is appreciated.

v a d e //

http://www.vade.info
abstrakt.vade.info

Re: jit.gl.render repeating context in imagebuffer

Wesley Smith — Tue, 17 Jan 2006 23:35:42 +0000

No there was a big discussion in november and render to texture does
not currently work at all. I agree that this (excuse my french)
sucks.

patiently awaiting 1.5.3
wes

Re: jit.gl.render repeating context in imagebuffer

vade — Tue, 17 Jan 2006 23:45:53 +0000

Ah. Thanks a lot Wesley for the info. I seemed to have missed that
conversation and didnt see it in the archives. I eagerly await a fix
for this. Id love to be able to render a whole scene to a texture and
then apply some sexy shader goodness to the output.

Thanks again -

v a d e //

http://www.vade.info
abstrakt.vade.info

Re: jit.gl.render repeating context in imagebuffer

wallace winfrey — Wed, 18 Jan 2006 04:25:27 +0000

> well, there’s not much choice really, if you want to/need to keep up
> with several topics, you need to subscribe to several lists.
> the unpleasant part is not being told about it.

I’m not sure what else I can do — let me quote from the Forums FAQ

–
* There sure do seem to be a lot of forum options now. I’m not sure which one to post in. Maybe I should just continue to keep sending all Cycling ’74-related emails to the MaxMSP list…

Please don’t! One thing we had hoped the new system would do would be to dilute the volume of the main list, and re-route the discussions to more appropriate topics. We will have a policy of moving threads that stray off-topic into a more appropriate topic.

* Wait! I participate on the mailing list and don’t really use the forums. How will I know that a topic has been moved?

We will make an announcement on the forum/list prior to moving the discussion thread.
–

So I made the announcement on maxmsp that this topic would be moving to the Jitter forum. Lilli also sent out a link the site FAQ, which has a link to the Forum FAQ. I’m not sure what else could be done in regards to informing people that a thread has moved.

cheers

–
wallace winfrey
wally@cycling74.com