[John Estes]

Dave,
Sorry. Is there a specific way you would like me to do that? I can import an image in and then in the footage pane (where you can switch from RGB to alpha) and it shows the alpha channel.

Here is the thing, I import to Nuke composting software and it shows no alpha on the video, but does on a image sequence. Then I import it into Vegas software and select it to be interpreted as “dirty” and it shows the transparency. So it seems to vary by software as to its being recognized. But I think the answer to your question is yes. Seems to show an alpha channel.

Though I can get confused on this, as far as I can tell it has an alpha channel. I just downloaded the new cine form as further research made the alpha support questionable.

Is there another codec for video that supports an alpha channel I can try? I prefer to avoid an image sequence.

Thanks

John

[John Estes]

Erik,
Nice to have a softimage user! I feel like I am in the minority there. I rendered out a .png sequence, and confirmed the alpha in nuke and in sony vegas. But when I put it in softimage and use the alpha as a transparency map, it doesen’t work. Not sure what you are referring to as the channel picker node, but I will see if I can find it.

As an aside, do you know how to get the still image sequence to play back in the preview window like a .avi does. All it gives me is the first still image ( just a seperate question for you).

Thanks,

John

[John Estes]

Dave and Erik thanks for your responses.

Let me try to get more in detail for you. I am generally knowledgable but not an expert in either application.

So, I rotobrushed a sequence in after effects. Specifically removed the foreground element.

Confirmed that there is a alpha Matte generated via the channels button. Image is black background white subject isolated.

My intent would be to export to an .avi that can accept alpha channels as the 4th channel. Inside Softimage I should be able to invert the channel but that doesn’t work.

From after effects:

I use cineform ( now GOPRO) as an intermediate codec.

In after effects, I selected it as the codec and confirmed RGB + alpha for render.

I rendered as lossless ( required by cineform to do the alpha channel thing).

( I have confirmed the presence of a RGBA it inside Nuke with alphas in tact as it deals more clearly with this stuff as far as I can tell ).

I bring it into softimage. Apply a phong with a image texture ( the .avi I expored with the alpha channel) and then inside the shader property page, I apply a transparency map by going to the ppg transparency tab and select the “use alpha” to use for the transparency (here I have the chance to invert it) When I do I get some funky half transparency.

Doing the same process with a still image exported from the composition ( that appears to be inverted) gives me a transparency (white) + RGB channel with a alpha transparency as it should be. But thisthing gets long and drawn out. Bottom line the same doesn’t work with the .avi.

[John Estes]

Cool. I will give it a try. Thanks so much for the help!!

John

[John Estes]

Good Ideas I will try.
You are generally able to create a corner pin for export into After effects. I know it works for tracking an item ( say rocket as it flies)
But I am unlear as to how it works to create a stationary effect within motion tracked footage.

I have just used the tracking in mocha as an offset in particle illusion.

I will keep you posted. Thanks for the help. I can post some footage for you to.

Thanks,
John

[John Estes]

Sorry if I was too vague.
I am trying use motion tracking of an object in Mocha to allow insertion of a explosion on a building.
I am planar tracking building in mocha, track appears solid.
I am exporting solved tracking data to particle illusion via transform data in mocha copy to clipboard.
I am in particle illusion now, and I click at the first frame, to place an emitter and then right click on offset>import
Copy data from clipboard.

When I view the footage, the tracking data appears solid for a while then starts suddenly jumping around.

My main issue is trying to get the layer offset in particle illusion to keep the explosion stationary. Maybe you could tell me your process for doing that? And I can go from there.

Thanks,

John

[John Estes]

That is what I was figuring on.
I do appreciate the comments and all the help.

Thanks,
John

[John Estes]

John,
Thanks for that info. Would have taken me 6 months to find that!
I will give that a try. If I had to then mix with 29.97 frames per second, I will have to do the pull down right?
–otherwise it will be going at 1/4 the speed at 29.97. Any suggestions on best way to bring the footage together without any significant visual loss?

Thanks again for your help.

[John Estes]

Steve,
Thanks so much for your response.
I actually ended up just solving the problem.

Mental ray has a image output selection drop down box.
It has a drop down for choice of image, choice of format( RGB) and choice for bit (8).

I had changed the file to .png but I did not realize until just now that there is a selection for RGBA that is in addition to the mental ray pass default which specifies RGBA as the heading for that pass, but obviously, the file format must be changed to the same. Not intuitive but it is the way it is.

Now the file opens without any changes to be transparent in the background.

If only I had a penny for every hour wasted on that one.

Thanks again for starting to help me there. It is appreciated.

John

[John Estes]

I uploaded the clip it is called samplempeg2clip.mpg

go to https://movementspecialist.com/john (note the blurryness and the pixelation on the arms) compare with the quicktime standing warrior pose file. Same workflow for each.

Of note: This is an uncompressed file from Ultraserious magic output 24 bit with flicker filter set to on progressive footage. It was encoded in vegas as MPEG 2 as listed in my original email. It does not have the second application of the “reduce interlace flicker” filter on (because that is done at the media level in DVD architect.”

Thanks so much for your time and effort guys and any input you have. I will try some renders without the flicker filters per the suggestions. I beleive I tried this, with no improvement.

Let me know if you need more clip–I tried to keep the file size small.

John