Realtime playback of composite

I am trying to learn to use the compositor.
So far so good (and I have read many pages of the wiki). But I am not sure I got the workflow down correctly. The main question is how to play back your video while compositing.
Here is what I figured out so far , please tell me where I may be missing it.
This pertains to compositing a video (not a 3d generated sequence) .

  1. Open the Node Editor view
  2. Make sure use nodes is on, and Composite nodes button is pressed, ( I delete everything in it ie the renderlayer and composite nodes.)
  3. add/input /image/ … then select my video from within the node.
  4. add a viewer., open another view ans set it to uv/image editor
    ----- at this stage , when I look in the uv/image E window, I can preview the viewer or my image directly.
  5. insert some nodes such as color correction chromakey etc inbetween image and viewer.
  6. Add a composite node, ( It doesnt show up in the uv/image editor, even when I select do composite . However this is the image in the render window, correct?) … so in my understanding to this point the composite node only goes to renderer …if you want to preview, use a viewer node.

7. Finish and render.

Did I miss any steps? … I concede, the steps performed do not necessarily have to follow in the order I perform them above.

So now the real question … Assuming I didnt miss anything. I notice the uv/image editor has a play button that doesnt seem to work. When I hit that button , I notice the little black box with frames moving in it as though something is playing. the only way I can get UV window to update is click the frames button in the image node . How do you get frames to play like it would do in say after effects or any other compositing package. So you dont check you composite frame by frame.
You obviously wont see issues related to motion ( eg matte chatter) if that is the way its done.

Any help offered will be appreciated.

To keep the above question readable I decided to ask this other question in another post.
How do you get the clip imported in the node editor to automatically show up in the sequencer. It would be nice if anytime you import a clip into the compositor, it would automatically link to the sequencer. Do I have this backward, Should I be importing the clip first into the sequencer before I composite, so they are linked? I tried that , but it didnt seem to work for me.
I dont really need to edit in the sequencer, just have a visual way to view frame in a time line.

thanks again

Cheers

–if you don’t delete the composite output node, you wont have to add it back in later.
3. add/input /image/ … then select my video from within the node.
–dont forget to enable move and specify the number of frames to sample
4. add a viewer., open another view ans set it to uv/image editor
–shift-D Duplicates that viewer node; we use a bunch of them to check wip.
5. insert some nodes such as color correction chromakey etc inbetween image and viewer.
–good idea :wink:
6. Add a composite node, ( It doesnt show up in the uv/image editor, even when I select do composite .
–It’s called RenderResult
However this is the image in the render window, correct?)
–Yes
… so in my understanding to this point the composite node only goes to renderer …if you want to preview, use a viewer node.
yes, or click Backdrop in the header bar.
7. Finish and render.
–Click Do Composite, and click Render for 1 frame, or Animate for a bunch.
Did I miss any steps? … I concede, the steps performed do not necessarily have to follow in the order I perform them above.
–Looking good
So now the real question … Assuming I didnt miss anything. I notice the uv/image editor has a play button that doesnt seem to work.
– mine doesnt, so you must have a better version than me.
When I hit that button , I notice the little black box with frames moving in it as though something is playing. the only way I can get UV window to update is click the frames button in the image node . How do you get frames to play like it would do in say after effects or any other compositing package. So you dont check you composite frame by frame.
– Inside of Blender, use the VSE channel 0 after adding the Scene as a strip. It is not guaranteed to be real time, based on the complexity of your noodle and power of your pc. Or render it out to a video and watch it.
You obviously wont see issues related to motion if that is the way its done.
– i have so many issues, I cant see them all either. I do try to exercise, but spend a lot of time in front of the computer, so my motion issues are limited. Thanks for asking, tho.
Any help offered will be apreciated

  • ur welcome

RogerWickes, thanks for simplifying it and filling out those little gaps in my understanding of the compositor .


Inside of Blender, use the VSE channel 0 after adding the Scene as a strip. It is not guaranteed to be real time, based on the complexity of your noodle and power of your pc
.
– I totally missed this one. So I just tried it, but the scene clip will only move down to channel 1, almost as though channel 0 is locked. At least I know what to look for now so I am going to research it.

i have so many issues, I cant see them all either. I do try to exercise, but spend a lot of time in front of the computer, so my motion issues are limited. Thanks for asking, tho. [quote]You obviously wont see issues related to motion ( eg matte chatter) if that is the way its done
.
[/quote]lol … OK, you got me on that one.:o I didnt phrase my point clearly.
What I meant was that going frame by frame would make you miss things like matte chatter and so on that you would only see with some sort of auto playback. :slight_smile: … but thats a moot point now, base on what you just showed me.(yet to get it to work… but I am trying).

– mine doesnt, so you must have a better version than me.
I am using 2.43 , in the viewer, there is a red Record composite button , next to which is a play button. When you click this button, the frame counter rolls , and wont stop till you hit the spacebar. Can anyone verify that I am not seeing things?

I have a few suggestions on features for the compositor. I will probably start a new thread or post it in a more appropriate place ( if this is not the right place for that.)

Thanks a million, this is just what I needed.
cheers

ah, ok. in the VSE, channel 0 is the output channel. Yes, you load your strip(s) in channels 1 through n, but the ultimate mixdown is played out of channel 0. see the wiki on the VSE. I wrote it, so if it isnt clear, hate me.

yes, to see like moire patterns, you have to play it in near-real time.

Ok, the window that you think is the UV with the record button isn’t. you are looking at the Timeline window, if it’s icon is a clock. The UV window’s icon is a very small but processed picture of my wife back when she was good-looking :wink: The timeline is used for scrubbing back and forth. Don’t touch the record button. Choose the Sequence screen layout and you’ll see it a little more clearly and be better able to see visually what it does.

This is not the forum for feature requests. that is now in the wiki at http://wiki.blender.org/index.php?title=Requests

Hello,

I had a few weeks ago the same question ( maybe you found my thread allready). I’ve used packages like after effects or shake, so I know what you are talking about with the realtime-playback… the answer, it’s hard to say, is: blender hasn’t realtime-playback at the moment, like we know it.

that’s why there is that record-button next to the play-button in the uv-image-editor. it creates a compositing-preview in the cache, which can be viewed with the play-button.

but there is no way to “scrub” in realtime through your composition, so that blender would automatically update the current frame with the composition (like we know it from after-effects)…

maybe one day…

Greetz
S.

i dont know AE and the power of the platform it runs on, but scrubbing in the VSE on my little laptop is realtime for me.

I would be amazed if AE could do a real-time node computation and display.

ah, yes … in the vse you are right !

but not when doing Node-Compositing, and i think that’s what the thread is asking for. (in my workflow vse is just editing and node-editor is just compositing, although the vse has raw compositing-features) after effects hasn’t any node-compositing so i have to say: realtime-scrubbing / realtime-node-compositing like one can do in shake…:wink:

Greetz
S.

gosh, I hate to disagree with you simhar, but I get real-time display of my Node compositing result. I think you just have to know how to configure it. When you click play, after it computes (takes me about 1 second per frame), it plays the scrub area…real-time at 30 fps.

:eek: :eek: :eek: :eek:

ha, yes, you are right, thanx for that advice! my fault! :smiley:

The only thing that doesn’t seem to work is, when i scrub directly with my mouse in the timeline (like you know from the “normal” animation) it only updates the image when i release the mousebutton. it would be fine to change automatically on frame-change interactively…

hope you disagree again… :yes: :yes:

Thanx
S.

Can’t disagree there, it works like a VCR and not an editing tape deck. The feature request page is open to all…but what you are asking for, namely dynamic real-time composition of a noodle, seems impossible to me, as some scenes take mintues or hours to compute, I dont see how you expect blender to compute it real-time.

Well
thanks guys for the input.
Its taken a couple of days to respond because I have been trying to figure it out.
Still no go.
Thanks anyways.

cheers

In the VSE, add a strip called Scene; it is the output from the Composite. When you click the play button, Blender calculates the frames and then plays it back in realtime.

Roger,
Thanks for your patience.
I have included a picture in the hopes I can figure out what I am doing wrong.
I numbered the image to make it easier to reference.
here is the link
http://zoogievision.com/blenderQ/compositorlearn2.htm

I tried that play button {#1}, but it didnt work ( Cos its tied to the viewer ?) ...I wonder why its there then. The drop down doesnt give me the option to use the composite view.... There is however a composite preview under VIEWER/View (shift+P), but that doesnt work either. Actually the composite preview even shows the same  matte image as the viewer even though my composite node is in color,. Its a direct feed from the source footage.. just so I can easily differentiate it from the viewer. (as shown in the second image)

I dont have the option to choose the composite view from the uv-image edit window as shown by dropdown {#4}
I tried the play button {#2} in the buttons window, but that doesnt seem to do anything. I also have the scene added in vse {#5} .
I have do composite and do seq. checked {#3}

I really hope I can use this as a functional node compositor ,so I am willing to do what it takes to learn it, but I just seem to be lost on this one.

thanks
Zoogie

1 Like

you are so darn close it isnt even funny. here: http://uploader.polorix.net//files/152/blender/realtime2.blend
just click the play button in the timeline header. the UV window is your wrong window, dunno what that play button does either, except waste my time. Look at not the UV window, but the VSE window in the display channel 0 mode, not strip mode.

You may have to wait for 3 seconds while blender runs the composites, but then it will play back your scrub in realtime. thanks for hanging in there, so much of blender is just one click away, if you only knew what that one click was…

ok, a few caveats: i shouldnt bash the UV window, it is good for looking at the current viewer node for the current frame, and is good for painting and uv mapping. but a real-time view it ain’t - that’s what the vse window is for. the vse has the strip mode, the picture mode, but also the color balance mode as well. see the wiki on the vse.

The file i gave you, if you load a pre-rendered movie in as strip 1 instead of the scene, the layout does real-time scrubbing back and forth - just click and drag in the timeline window.

the bigger the pic and the more complicated the noodle the slower that first run-thru will be.

Roger,
Got it finally, thanks for the file. Made it clear.
Thanks a million