Media Textures With Alpha - render through sequencer Tweet

[joshuamkerr]

I'm right at the end of a shot I've been working on. I brought a media texture into unreal, a pre-keyed actor so it's an rgb + alpha texture to be played in the environment.
I hit a hurdle earlier when I realised that the octane didnt recognise the alpha channel from the material and just rendered it black. But I found a way around this by creating a second media texture just with the alpha chanel represented at white on black, then plugged it into the opacity pin. This worked to remove the black and now I have two textures playing in sequencer.

But now I have hit another wall, when you play back in sequencer it takes time for both textures to catch up to each other and I get drift between the RGB and the alpha map when rendered through octane. This shouldn't happen because both are the same frame rate and length, however it seems that frames get submitted to octane for render before unreal can catch up.

I was wondering 3 things.

1) Is it possible to make the alpha map work with one material and eliminate the need for two textures. I have not seen a way to use media textures in octane materials.
2) Is there a way to delay the render from octane until unreal has caught up or updated correctly?
3) Am I missing something very basic that would solve the problem I have not thought of?

I really hope theres a solution to this. It would be such an amazing thing to be able to pull off.

Here is the export so you can see the result
[youtube]https://youtu.be/lzw45rStwHQ[/youtube]

[ChrisHekman]

The next build will have alpha for media textures. I hope to publish the new build this week.

But now I have hit another wall, when you play back in sequencer it takes time for both textures to catch up to each other and I get drift between the RGB and the alpha map when rendered through octane. This shouldn't happen because both are the same frame rate and length, however it seems that frames get submitted to octane for render before unreal can catch up.

From what you describe, this should not be happening. Ill check if I can recreate this issue.

Here is the export so you can see the result
[youtube]https://youtu.be/lzw45rStwHQ[/youtube]

Which export are you using? Overlay?

[joshuamkerr]

Hi Chris,

Firstly, that's great news! It's a major feature for people looking to do in engine compositing. I look forward to the next build.

I'm not sure what you mean by overlay, could you elaborate? Where would I look to check this?

[ChrisHekman]

Hi Chris,

Firstly, that's great news! It's a major feature for people looking to do in engine compositing. I look forward to the next build.

I'm not sure what you mean by overlay, could you elaborate? Where would I look to check this?

Sorry, I ment "Octane Integrated", in the code I call it "overlay mode"
This mode which will copy the octane render results into unreal. Sadly this mode can sometimes cause mismatches because of how unreal provides data to the plugin.
Basically "half-frame" behind issues.

The other modes are:
Octane Export (ORBX)
- Exports to an animated orbx file, that can then be rendered with ORC/RNDR or with standalone octane
Octane Render (Image)
- Exports the octane render results directly to images

[joshuamkerr]

Aha! I see what you mean. I'm using the Octane Render (Image) export setting to create an exr sequence.

I'd love to know if you can replicate the issue. I have quite a simple setup as described.

1 material with 2x media textures. 1 is rgb colour and the other is rgb alpha (white on black). No other nodes
Both are set to play back in sequencer simultaneously
Cine camera is place in front of the a plane with the material applied
Render Octane exr sequence.

[joshuamkerr]

Sorry Chris, I forgot to ask, where do you publish the new builds for Unreal?

I'd like to keep my eyes peeled for the next version with alpha support.

[ChrisHekman]

Sorry Chris, I forgot to ask, where do you publish the new builds for Unreal?

I'd like to keep my eyes peeled for the next version with alpha support.

I publish them here on the forum: viewforum.php?f=132
And via the download page on otoy.com: https://render.otoy.com/account/download_archive.php
*otoy.com might take a while longer though

I also found the underlying issue with the mismatch between octane and unreal when it comes to mediatextures, but will need to do more testing before I can publish the next build.

[ChrisHekman]

Hi Chris,

Firstly, that's great news! It's a major feature for people looking to do in engine compositing. I look forward to the next build.

I'm not sure what you mean by overlay, could you elaborate? Where would I look to check this?

The build is out here: viewtopic.php?f=132&t=78743
Let me know if it works for you.

[joshuamkerr]

Hi Chris,

Glad you have a new update out for media textures and sequencer. I'm working in 4.26, is there an update to this one?

[ChrisHekman]

Hi Chris,

Glad you have a new update out for media textures and sequencer. I'm working in 4.26, is there an update to this one?

Ive added a 4.26 build.

However, Im going to deprecate 4.26 support for next build due to Niagara differences.
Is there a specific reason you are not upgrading to 4.27?