Trouble Rendering Alpha Channel Image Sequence Texture

[boik]

Howdy,
I am having trouble rendering a plane with an image sequence texture (.iff with alpha channels) placed onto a polygonal plane. Everything works fine with a playblast and when rendering a single frame. However, when attempting to render all the frames into any sort of movie sequence (.mov, .iff) upon playback all I get is a dark screen. I have tried rendering on various networks, and computers and I get the same result.

The shader is a lambert with a 2d file (the file is a .iff sequence created in adobe after effects) attached.
I am rendering using a the maya software renderer.

If there are any suggestions or solutions please let me know, thanks!

[3dinsd]

for clarity, did you create the IFF sequence in AE? It sounds that way.
go into hypershade and graph the network of the material you're assigning to the plane. If it has a connection from the 2D texture to the material as transparency then delete it.

Re-render and see if that fixes the problem.

If your polygon plane needs an alpha channel, render it out in AE as a separate sequence and assign it to the material as transparency.

-Jason
3dinsd@gmail.com

[boik]

Hey,
Thank you for the intelligent feedback, unfortunately I'm still stuck with the same problem though I think I understand it a little more fully now. I heeded your advice and found that I was still dealing with the same problem- any batch render performed the assigned texture sequence would not show up at all( with or without an alpha channel). The planes and everything else will render but the image sequence simply isn't showing up. However, I did notice when trying various setting and file types that the only thing that will render is a quicktime movie movie texture. This would be an acceptable solution to my problem if only the images didn't have any interference (there are strange lines going through the images... I don't know what to make of them) it may be that my format is unsupported (this was a "lossless" output setting in AE so it doesn't make sense that it would be a compression issue) -do you know of any compatable movie formats for maya or a solution to this problem? I also observed that when I had multiple planes that had loaded image sequence textures that only one would actually playblack in the window at a time. It was always the most recent texture that I added to a plane that would work- the others automatically stopped. If I reattached the image sequence onto any of those that had stopped working it would animate again but all others would stop. I really am at a loss on how to tackle this problem. I suppose I really don't understand fully this process, do you know of any tutorials that might walk me through this animated texture stuff?

note: I am attaching the image files to the color section of the lambert shader and then I click the "use image sequence" button which(correct me if I am wrong) allows the images to load with the corresponding frame number from the scene.

I am running maya 7.0 off of a powerbook g4 1.5 ghz 768 ram osx 10.4.4

[joojaa]

post asimple ma file that has the sympotom!

[3dinsd]

Berk,
There are definitely tutorials around, but I don't have a link handy. As Joojaa always rants: Do NOT use a Movie node for file textures or for rendered output.

Here are the steps:
1. In AE, send your comp to the Render Queue.
2. Output single frame 24-bit TIFF images with the naming exactly like this: name.[####].tif
3. In Maya, create a polygon plane.
4. Assign a new lambert material to the plane.
5. Assign a 2D file texture to the Color attribute of the lambert material
5a. Slide the ambient color value of the lambert to 1.0 (white)
6. Browse for the first frame of your image sequence.
(**are you rendering frame 1 to X in your AE comp? If not, use the 'offset' parameter in the 2D file texture attributes to match the starting frame in the image sequence to the maya timeline. Watch for errors/warnings in the Maya command feedback window)
7. Before rendering, scrub your timeline while viewing your scene with hardware texturing enabled. You should see the image sequence updating as you scrub.
8. Render a couple test frames. How's it look? If ok, batch render. But only batch render a small set of frames, like 1-10. Verify that they render correctly then go back and batch your entire scene.

Based on your last email it sounds like you'using an image plane attached to the camera, not a polygon plane. You're using a polygon plane, right?

I re-read your original email. So in the render view, the rendered image looks correct. But when batch rendering it comes out black? Do you have any other objects in your scene? Do they render ok? Use Fcheck to play back your rendered sequence. Perhaps QTPlayer or AE is mis-reading Maya's rendered output. I see that all the time in Premiere and AE-- it treats Maya's alpha channel as untagged and your image sequence appears black.

If this works, we can talk about using the alpha channel from the image sequence.

-Jason

[boik]

Jason,

Okay, I followed your steps as closely as I could. I would say exactly but I'm not quite sure what you mean in step 6 when you say to use the "offset" parameter in the 2D file texture attributes- are you referring to the frame offset option? If so then I am afraid I don't know how to operate those particular options- the expression editor is still somewhat foreign to me. Anyways, the AE output file looks like this name.[####].ext
or more precisely hand.0000.tif.

Concerning steps 7 and 8 I observe these results. Upon applying the texture as stated in steps 5 and 6 (I am clicking the use image sequence button, which I believe creates an expression that looks like this: file1frameEtension=frame, Initially this seems to work as I scrub through the timeline I see my image sequence changing with the corresponding frame) I get the desired results. I can scrub and even perform test renders of single frames and I get exactly what I expect. However, a batch render is still giving me the exact same results ( I have rendered with other objects and they are rendering which indicates that my problem is somewhere within the realm of my 2d texture) the polygon planes will render completely black (the planes will still obstruct objects behind them with or without alpha channels).

Okay, here is a big mystery for me, after applying these 2d textures they seemingly at random automatically disconnect the file. I have to then go in and reattach the files to the shader. I have noticed that this will always happen if I add any new shaders into the scene that have image sequences as textures. I need to find a solution to this problem as well because I plan on using multiple image sequences on multiple planes in my scene.

I am really at a loss here and I appreciate your input I finally feel (after weeks trying to figure this out) that I am getting closer to a solution.

Thanks much,

-Berk

ps Jooja you suggested posting an .ma file with the problem- won't I need to also include the image-files that are linked to the shaders? Also, I admit I am not a regular to forums and I'm not even sure how to attach a file to any posts.