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movie sequence in opacity channel, pls.

PostPosted: Fri Mar 01, 2019 2:54 am
by protovu

This is something I rely on in my other Octane plugin (Carrara).

Specifically, I drop a grayscale AVI in the opacity channel of a material.

This allows me to have a opacity crawl over a surface, for example, but there are many variations I have used.
movie start finish keying.PNG

But, within the encircled of the above image, no keyframing is permitted.
I cannot specify a start and end point without the keyframing. I can only specify an offset, but not keyframe the offset.

How can I drive the AVI?

Your help appreciated,

Re: movie sequence in opacity channel, pls.

PostPosted: Fri Mar 01, 2019 9:51 pm
by ChrisH

The problem here is actually with Blender, since it's Blenders imaging handling that's used. The Octane team would have to write their own "image handler" for Blender to fix this.
(In 2.8 you can actually set keyframes for Offset, that's slightly more helpful).

You can adjust the start frame, but that's just "one shot".
And I agree, there should be a way to have more manual control over the image sequences (for textures), similar to how you can control curve animations.

There's two ways around this, both are less than optimal and rather "botchy":
  • Edit the sequence outside of Blender/Octane to match your desired result
  • Use several Image Texture nodes, with different Start etc, and then use Mix Texture to switch between them (as you can keyframe the Mix amount)

(NB: Octane actually don't support using movie files for textures, the plugin saves the right frame as an image and sends that to Octane)
(Also, if your using greyscale images/connecting them to greyscale inputs [like opacity], use the "float image texture" [called "Greyscale image" in the Standalone], it uses 1/4th memory [and might speed it up some!?])

Re: movie sequence in opacity channel, pls.

PostPosted: Sat Mar 02, 2019 12:42 am
by protovu
Hi Chris,
Thank you for the response.
I understand. Sort of disappointed as this is a very handy tool. As mentioned, I am able to use it in Octane Carrara, but as you point out, Carrara is the enabler here.
I have always been able to use AVI files with Octane to do this. Able to keyframe anywhere in the AVI sequence to move in any direction.

I will most likely use a series of mix nodes, animating between two images at a time to achieve the result.

In this case I am effectively causing a bloom of color on a plane form. Not terribly elaborate.

You indicate that Blender 2.8 has this capability. When will the Blender/Octane 2.8 suite roll out?


Re: movie sequence in opacity channel, pls.

PostPosted: Sun Mar 10, 2019 8:40 pm
by protovu

The .avi files are working basically as desired in the opacity channel.

Capabilities at this point:
they can start on a chosen frame and play through.

they can mix .

Cannot, or I cannot figure out, how to play them forward and backward ( could do some mixing to accomplish, though ).
Not sure about looping.


Re: movie sequence in opacity channel, pls.

PostPosted: Sat May 23, 2020 9:13 pm
by protovu
What happened to .avi controls in the shader channels in 2.8?

They were great for controlling opacity or mixing factor in 2.78.

Controls are not working: Frames, Start Frame, Offset, Cyclic.
Worked perfectly in 2.78. Any ideas?