Composite hiccup

[Simon Edmondson]

Working away on the current project. I rendered the sequence out as a series of TGA files to be composited over a cloud background.

Then used a chor to composite them within AM. With this result,

 

S6_Clouds.mov

 

There are two moments when there are distinct movements which should not be there, frame 65 ( 02:15 ) being the first. Checked the new composite file and this was the result. There is a shadow behind the figure,

 

 

I went back to the original, Which looked like this,

 

 

Using the same files as for the AM composite, I then did it again in FCP and got no glitches,

this is frame 65,

 

 

Should add that, the original were rendered with Toon settings but the composite was not, no lights or shadows were used but, multi pass was.

 

It seems to have placed a different plane while rendering one as a 'ghost' image. A similar thing happens on frame 166, ( 06:16 ). I don't know why this has happened, could anybody kindly suggest the cause and possible cure ?

regards

simon

 

PS

I was hoping to use the composite and multi plane options within AM for the next part of the short so would like to get it right

[Rodney]

There is a lot we don't know about your setup but if you set your background plane to receive no shadows that should keep the shadow from appearing.

I'm not sure why it would appear on only those frames except to say that perhaps you rerendered some frames or terminated a render before it re-rendered the whole sequence.

 

You should also note that if compositing your images within the Chor the lighting will cause cutouts to cast shadows by default.

One way to get past this is to drag/drop your lights onto specific models thereby creating a Light List for which objects will be lit and shadowed.

Another way is to remove the lights from the Chor which you are using for compositing.

 

To bypass all of the lighting issues you might also use A:M Composite via the PWS, which does take a little experimentation to learn.

[robcat2075]

Yes... are you doing this as a Composite project in the Images folder or in the Chor?

[Simon Edmondson]

Yes... are you doing this as a Composite project in the Images folder or in the Chor?

 

Robert and Rodney

Thank you for your replies.

I was working in the chor using layers for both the background image of the clouds and the foreground of the figure on the set. No lights were used in the chor at all, and the shadow option was turned off in the render panel. ( I was unaware that you could do a composite within the images folder ? )

 

Apologies for my error on the description, I meant that there is a darkened area behind the figure in the first image, it shows up on the cloud and takes the form of a silhouette shape. It looks as though it could be a shadow but, the figure is not in that position on that frame.

 

The sequence was rendered completely in one overnight session and the list runs correctly in the image folder. It was imported into the images folder and applied to a layer, that layer positioned over the background layer of the clouds. a camera framed on the layers, then rendered out as a second sequence.

 

What seems to have happened is that a frame has been used out of order within the chor and the render has interpolated between the two ?

 

If the exact same sequence is used within Final Cut Pro and over layed on the cloud image, then it is as expected, with everything in order and no 'tweening'

 

regards

simon

[Rodney]

No lights were used in the chor at all

 

 

We will assume you deleted the default lights in the Chor then manually.

 

When performing a straight composite in a Chor it is generally better to use Rotoscopes than Layers. Layers work better for when you are moving images around, scaling them, etc. If your clouds are all of such then I see why you used Layers but generally I would still use a Rotoscope for the overlay in the front (Just make sure to set the setting 'On Top'.

 

If there is something off in your original sequence then you have found your solution. You have to scrub through your sequence and remove/replace the frames that do not belong. Not sure how they got there but I postulated as to one reason they might be there in my last post. If for instance you rendered a 24 frame sequence with shadows on and then rendered again with shadows off but this time didn't render all 24 frames... well... that'd result in any of those frames not rerendered still having the shadow.

 

Without having access to the project itself there is a lot of guesswork here.

From your images though it sure looks to me like that one frame has a shadow and for that to happen there would need to be a light shining at some point. Other objects in the scene (the bench for instance) are also casting shadow so there was/is light there at some point.

 

As this matches with why you wouldn't be getting this same effect in Final Cut Pro (i.e. in Final Cut Pro you wouldn't have any of A:M's lights) my diagnosis is still that you are casting unwanted shadows with lights. BUT... the most important thing is to make sure the sequences you are using are rendered numbered right.

 

You might also try to render with Multipass set to OFF. (with no multipass and no blur A:M will not attempt to blur between frames)

 

I need to reread your descriptions... Do I understand that you are only using images in A:M or do you have your models in front of the layers and background?

[Simon Edmondson]

...

 

I need to reread your descriptions... Do I understand that you are only using images in A:M or do you have your models in front of the layers and background?

 

 

Rodney

Thank you for your help. I will go back to look again at the frames rendered but, as you suggest at the end, I am only using images .

 

I rendered the scene with a blank sky and an alpha channel as a TGA sequence.

I rendered the clouds separately as a single image.

 

Scene frames rendered in AM as, "Why Scene Six" 000- 280 .tga,

Cloud rendered as single image in AM.

 

New Chor set up,

All lights deleted, no ground, no other objects,

The cloud image was the background layer

The scene sequence was the foreground layer, with the alpha allowing the clouds to show through.

That was then rendered out as a new sequence, "Why Scene Six C" 000-280.tga

 

When the C sequence was saved as animation the problem became apparent.

Went back to check the C frames individually with the result as posted above.

 

Tested the original scene sequence and cloud frame in FCP, no error in sequencing.

Just tested it again, this is the result, ( its a bit compressed but no sequence error ? )

 

regards

simon

 

FCP_6_Clouds.mov

[Rodney]

Can you share the Project file (without any of the images/models/assets should be fine).

That alone might be able to shed some light on the subject.

[Simon Edmondson]

Can you share the Project file (without any of the images/models/assets should be fine).

That alone might be able to shed some light on the subject.

 

Rodney

Thank you once again for your help. Much appreciated.

 

Might be a bit tricky without images (?) but here is the project file without images or models.

regards

Simon

 

Why_Composite.prj

[robcat2075]

Can you share the Project file (without any of the images/models/assets should be fine).

That alone might be able to shed some light on the subject.

 

Rodney

Thank you once again for your help. Much appreciated.

 

Might be a bit tricky without images (?) but here is the project file without images or models.

regards

Simon

 

Why_Composite.prj

 

Yeah I can't tell much from that. Have you tried just making the image rotoscopes in a camera in a blank chor? I think you can have more than one and can adjust their order by dragging in the PWS.

[Rodney]

Sometimes we can tell a lot by what we don't see...

 

Not that it matters (esp. if there are no lights in the Chor) but I do note that both Layers are set to receive shadows.

It also appears that at one time the Camera might have been set to save out Light buffers.

Not really a guess at the problem but more of a ruling out for myself... if a light Buffer'd image was somehow thrown into the midst of the sequence... that might account for the odd frames.

[Simon Edmondson]

Sometimes we can tell a lot by what we don't see...

 

Not that it matters (esp. if there are no lights in the Chor) but I do note that both Layers are set to receive shadows.

It also appears that at one time the Camera might have been set to save out Light buffers.

Not really a guess at the problem but more of a ruling out for myself... if a light Buffer'd image was somehow thrown into the midst of the sequence... that might account for the odd frames.

 

 

Robert and Rodney

Thank you once again for your help. I think I'll just use FCP on this one, then try to address the problem properly with the next scene, because I can keep track of what was done as I go through it.

The light buffers possibly stem back to an experiment a few weeks back when I found out about using EXR and the option of adjusting the lighting after the render. I rendered a scene and kept the info,but haven't had the chance to pursue it further yet. I will try to restore the default settings to the camera for the next scene in the current project, to be able to track the process properly.

regards

simon

[Rodney]

The light buffers possibly stem back to an experiment a few weeks back when I found out about using EXR and the option of adjusting the lighting after the render. I rendered a scene and kept the info,but haven't had the chance to pursue it further yet. I will try to restore the default settings to the camera for the next scene in the current project, to be able to track the process properly.

 

When troubleshooting its always good to eliminate unnecessary variables and this represents one.

It would be better to start with a new Chor and then delete everything anew rather than modify an old Chor that might have some setting you don't want.

 

If you've got Final Cut Pro then you are well into a very effective compositing workflow so you may want to stick with that.

As I mentioned before, if wanting to use A:M for straight up compositing and post effects there is also A:M Composite.

Robert does a nice demo of how to use A:M Composite with FakeAO in this video tutorial. The primary Post Effect I use when composting 2 or more images is 'Mix'. We can get some nice transitional fades by animating the percentages between the images.

 

One of the benefits of using A:M Composite is that we can use the resulting images created with it 'live' in A:M. (i.e. save or render out a complex composite and see that automatically update/effect a scene or character in A:M). Granted, this level of use would require much experimentation and at this point is far beyond your current need in compositing.

[Simon Edmondson]

 

Rodney

Thank you for the info and the link to the tutorial video, downloading it now.

On a related theme, do you know of any useful links on Matte painting and useage. I was thinking of using it for the next scene as a tryout for the next project.

regards

simon

[Rodney]

On a related theme, do you know of any useful links on Matte painting and useage. I was thinking of using it for the next scene as a tryout for the next project.

 

None that are specifically A:M-related but basically any 'behind-the-scenes' presentation these days will contain elements of matte painting, compositing and related themes. The older ones to look for are mostly from Disney who pioneered the process on the one hand and Ray Harryhausen as the pioneer of miniatures. The entire history of CG is basically the quest to juxtapose artificially created images in with those that are real with the goal to have the audience not perceive (or care about) the difference.

 

There is so much information out there it helps to have a target to shoot for and perhaps a list of expected obstacles or limitations.

 

Since we are talking in terms of compositing it'd be good to consider rendering in passes as well.

For instance, if you have a long shot where the camera begins at a close-up but then pushes back and out and up leaving the characters and presenting a view of the surrounding mountains what you'll need is obviously more than a 2D matte but... you can model the closeup and the environment separately and then composite them together separately. In this way you can concentrate on what is important in each area without losing the focus the entire scene needs. For rendering purposes you might simply duplicate those Chors and never again (until compositing) shall the twain meet.

 

Your question was a simple one and I've run off on another tangent.

I suppose the real answer is "No, at the moment I cannot think of any particularly useful links."

[markw]

Hi Simon,

The closest I can think of to traditional film mattes would be using layers in A:M.

There is an introduction to using layers on the ExtrasDVD; Tutorials > Layers. Or you can find it online here; http://mossor.org/Desktop/Tutorials/Layers/layers.html

 

As Rodney says the uses of mattes is a large subject!

Mattes were used in film originally because of the limitations of two things, budget & reality!

Though budgets still remain, in a computer reality is ours to play with! We now have infinite space in which to build and film, our only limiting factor being how long we are prepared to wait for frames to render. Which is where compositing comes in handy and when done well, impossible to spot.

[Simon Edmondson]

Mark and Rodney

 

Thank you for your feedback, I shall follow up the DVD extras link later.

I'm thinking of the Charlie Birthday project, there are a few open air landscape scenes in that and, rather than build a whole landscape, thought it might be best to try a matte so, in the current project, he's about to go walking in the mountains, bemoaning his fate. That seemed like a good way to test mattes in landscape!

Bound to get it wrong but it will be fun finding out.

Thanks for your help.

regards

simon

[Bruce Del Porte]

Hey Simon,

 

Animation has been produced as composites almost from its invention. There are a lot of both artistic and production productivity advantages.

 

If you have Final Cut Pro, or any other NLE for that matter, building your scenes as composites is well worth learning. The biggest advantages I have found are

 

1. It cuts iterative render time way down because you don't rerender models that have not changed between versions

2. It simplifies lighting, allowing you to light actors and their surroundings separately without lights from one interfering with the other.

3. You can also use different focal lengths for the actor than the background.

4. You can adjust lightness and contrast of layers in FCP separately

5. A lot of times you can render just one frame of a static background, a huge render time saver

 

You will need to learn to make separate shadow passes, and how to manage camera moves but both will become easy with just a little practice.

 

A couple of tips for best results:

 

1. You will probably want to render to TGA sequences. PNG sequences or Animation .mov files work ok but I have had the best luck with TGAs

2. Change the camera background color to black and as you load the the sequence into FCP, set the alpha channel description as "premultiplied" with black.

 

Every scene in Rear Window LHOOQ is a composite, assembled in a NLE. Compositing was a huge productivity boost. In the scenes you are doing for Why?, you could easily separate the characters from the background and each time you tweak, only render out the models that you changed. It is well worth learning.

[Simon Edmondson]

Hey Simon,

.... It is well worth learning.

 

 

Bruce

Thank you very much for your reply and the info. I will try to do the next scene as a composite, then post the result in the Why thread.

regards

simon

[Simon Edmondson]

Trying to use multi plane as a composite ( to get used to the process and thinking needed ).

I rendered out each of the clouds separately as TGA files with Alpha then used them to make layers.

The rain doesn't really show up under the clouds ( due to the scale ? ), so put a rain shower in the foreground.

 

This is the result. It is only 25 frames long so needs to be cycled.

 

Why_Rain.mov

 

Two questions

 

1

Is it possible to cycle the image sequence on a layer in the same way as it is possible in a chor, on a flat, using "post extrapolation". The show more than drivers option does not appear to be there in the PWS on a layer ?

 

2

There are no key frame changes in the timeline but the frame appears to partially drop out. Can anyone suggest a possible cause for that ?

regards

simon

[robcat2075]

1

Is it possible to cycle the image sequence on a layer in the same way as it is possible in a chor, on a flat, using "post extrapolation". The show more than drivers option does not appear to be there in the PWS on a layer ?

 

An image sequence has a frame property that can be keyframed and post extrapolated. If that really is absent from a Layer, remember you can always decal an image to a simple flat plane model that should have all the normal properties available.

 

2

There are no key frame changes in the timeline but the frame appears to partially drop out. Can anyone suggest a possible cause for that ?

regards

simon

 

I looked at the clip but I'm not sure what is "the frame"

[Simon Edmondson]

1

Is it possible to cycle the image sequence on a layer in the same way as it is possible in a chor, on a flat, using "post extrapolation". The show more than drivers option does not appear to be there in the PWS on a layer ?

 

An image sequence has a frame property that can be keyframed and post extrapolated. If that really is absent from a Layer, remember you can always decal an image to a simple flat plane model that should have all the normal properties available.

 

2

There are no key frame changes in the timeline but the frame appears to partially drop out. Can anyone suggest a possible cause for that ?

regards

simon

 

I looked at the clip but I'm not sure what is "the frame"

 

 

Robert

Thank you for your reply. You're too fast though !

I was just about to add a correction on my part. Found were the problem lay, but not the cause as yet. The problem lay with the rain layer, which was in the foreground.Re rendered, without the rain layer, with this result

 

Why_Rain.mov

 

Its a bit strange, as the animated frames that are on the layer, should be static ( with the rain passing through ) but the border edge of it appears to descend during the sequence, causing the problem.

 

If the cloud was decaled onto a flat would it retain the transparency of the alpha channel ? H'mm, I'll try to find out.

regards

simon

[robcat2075]

If the cloud was decaled onto a flat would it retain the transparency of the alpha channel ? H'mm, I'll try to find out.

 

If you set it as a "cookie Cutter" decal the alpha channel in the decal will also create transparency in the model.

[Simon Edmondson]

If the cloud was decaled onto a flat would it retain the transparency of the alpha channel ? H'mm, I'll try to find out.

 

If you set it as a "cookie Cutter" decal the alpha channel in the decal will also create transparency in the model.

 

Robert

Than you very much for that. I've never used a cookie Cutter -didn't know what they were for to be honest- Now is the time to try.

regards

simon