Transparent backgrounds in animation: techniques using zbuffers/postprocessing??

[LetItGrow]

Hello everyone, I know this has been mentioned before but I hope to gain some clarity regarding the use of zbuffers to create transparent backgrounds in animations. Considering that MB3D does not support alpha channels, achieving transparency obviously then requires post-processing. I would like to be able to completely delete the portion of the fractal which corresponds to the black areas of its respective zbuffer, and across all frames. My purpose in doing so is so that I can underlay images or videos behind the fractal structure to create interesting backgrounds which can still be seen through the 'holes' and openings within the fractal structure. This is easy to do in Photoshop for single images by creating masks and layers, but I need to be able to apply this to all frames making up large animations (1000s of frames). I suppose it would be possible to automate this process for each frame in PS using macros/actions etc., but it seems this would be highly inefficient.

I have attempted this in After Effects but have very little experience with the program (I access it through my university) and couldn't figure a simple way of creating transparent backgrounds on every frame of the fractal using the zbuffer.

Another method I tried with partial success (and not using the zbuffer) was to render the fractal with a background image consisting of some solid color which greatly contrasts the fractal colors, and then keying it out in AE--essentially the same process as green screen. However, during deep zooms some of the background color remains on the edges of the fractal structure, and in the process of keying this residual background color much of the fractal is removed; I think it is the fog and lighting features that cause this.

If anyone knows how to create transparency in After Effects or any other software, I would greatly appreciate instruction on how to do so. There must be some way to 'force' transparent sections on the fractal for all areas that are black on the corresponding zbuffer, either through batch-processing all of the individual frames, or by using masks and such in video compositing software. I have read the following threads but unfortunately they don't seem to indicate exactly how to perform the post-process removal of areas to create transparent sections--My 'trade' lies within agricultural research and so video manipulation is not my forte!!

http://www.fractalforums.com/help-and-support/transparent-background-t22425/
http://www.fractalforums.com/feature-request/animation-with-transparent-background/

Thanks  

[Sockratease]

Hello everyone, I know this has been mentioned before but I hope to gain some clarity regarding the use of zbuffers to create transparent backgrounds in animations. Considering that MB3D does not support alpha channels, achieving transparency obviously then requires post-processing. I would like to be able to completely delete the portion of the fractal which corresponds to the black areas of its respective zbuffer, and across all frames. My purpose in doing so is so that I can underlay images or videos behind the fractal structure to create interesting backgrounds which can still be seen through the 'holes' and openings within the fractal structure. This is easy to do in Photoshop for single images by creating masks and layers, but I need to be able to apply this to all frames making up large animations (1000s of frames). I suppose it would be possible to automate this process for each frame in PS using macros/actions etc., but it seems this would be highly inefficient.

I have attempted this in After Effects but have very little experience with the program (I access it through my university) and couldn't figure a simple way of creating transparent backgrounds on every frame of the fractal using the zbuffer.

Another method I tried with partial success (and not using the zbuffer) was to render the fractal with a background image consisting of some solid color which greatly contrasts the fractal colors, and then keying it out in AE--essentially the same process as green screen. However, during deep zooms some of the background color remains on the edges of the fractal structure, and in the process of keying this residual background color much of the fractal is removed; I think it is the fog and lighting features that cause this.

If anyone knows how to create transparency in After Effects or any other software, I would greatly appreciate instruction on how to do so. There must be some way to 'force' transparent sections on the fractal for all areas that are black on the corresponding zbuffer, either through batch-processing all of the individual frames, or by using masks and such in video compositing software. I have read the following threads but unfortunately they don't seem to indicate exactly how to perform the post-process removal of areas to create transparent sections--My 'trade' lies within agricultural research and so video manipulation is not my forte!!

http://www.fractalforums.com/help-and-support/transparent-background-t22425/
http://www.fractalforums.com/feature-request/animation-with-transparent-background/

Thanks  

Hello and welcome to the forums  

I may be able to help with this one!

First, in AE, make a composition containing both of your image sequences  (fractal stuff + z buffer).

Then add your desired background.

Then go to the fractal image sequence and set the "track matte" to your z buffer.  The trick is to then change the track matte from "alpha" to "luma."

That should do it!

Here's a screen shot to show what I mean - I used a magenta solid for a background layer to show it's working.



This does make the fractal itself partially transparent, but it's a good starting point.

Unfortunately, your best bet is to switch to a program that outputs an image with an alpha channel, like Mandelbulber.  I never got past Mandelbulber's Interface, so can't help at all with that program, but it is definitely the only professional solution.  Any effort to use the Z Buffer as a mask will require work to perfect the technique and there may be unwanted spots of transparency in the fractal or bad edges (especially if using fog - which is never a good idea with transparency!).

So definitely give Mandelbulber a look, and if you can learn how to use it there is no better solution for what you want to do.

Hope that helps.

Any questions, feel free to ask!

[LetItGrow]

Thanks Sock, this is very helpful, and I appreciate the detailed response! I have been a lurker for a while and your posts always have proven to be, without fail, very thorough and insightful. I will definitely play around with this some more.

I am going to try and experiment a bit more and hopefully can come up with something good. I think the color keying method may reasonably work if all fog settings in MB3d are left off, and then if desired, implemented in post processing using depth of field etc. Probably still won't be perfect though.

I'll have to try Mandelbulber too! I just kind of went straight into MB3d and stuck with it ever since. Certainly the support for alpha channel would prevent all of this extra work in the first place and would look much cleaner.

[Sockratease]

Glad it helped, and thanks for the kind words   

I was thinking about ways to keep grey areas of the z buffer from fading the opacity of the fractal - perhaps a carefully applied "threshold" or "curves" effect could make anything not almost "pure" black into white.  AE is quite powerful and the effect can be applied to the entire sequence, and even keyframed to make problem areas have different settings.

But again, a lot of work when there are alternatives which export images with alpha.

...I'll have to try Mandelbulber too! I just kind of went straight into MB3d and stuck with it ever since. Certainly the support for alpha channel would prevent all of this extra work in the first place and would look much cleaner.

Yes, I did the same thing.  I have been meaning to try the new interface in Mandelbulber 2.X, but I'm an old dog and new tricks are not as easy as they were in my long lost youth.  Something about the ease of MB3D just spoiled me for many other programs.

If I ever get ahead financially enough to have the time, I have a large list of programs to learn!  And Mandelbulber is near the top.

Until then, I'll stick with what I have and keep hoping to get time for learning again   

[mclarekin]

I know what you guys mean, I started with Mandelbulber and thought I would very soon try MB3D (plus others programs) but exploring the infinite in Mandelbulber has kept me busy for two years and I still have not tried all the other amazing programs.

My two cents, if you want to create animations, then when Mandelbulber 2 has OpenCL Option reinstated (which is high on the to do list) , the rendering speed will make Mandelbulber a very good choice.  (as the old Mandelbulber 1.21 OpenCL  still is.)  I would suggest wait for Mandelbulber V2.06, learn how to animate with it, then when V2.08? is released, switch to OpenCL rendering if you have a suitable GPU, 

What I need is free VirtualDub type program that can handle the png with alpha channel, does anyone know of such a thing?

Cheers

[Sockratease]

I know what you guys mean, I started with Mandelbulber and thought I would very soon try MB3D (plus others programs) but exploring the infinite in Mandelbulber has kept me busy for two years and I still have not tried all the other amazing programs.

My two cents, if you want to create animations, then when Mandelbulber 2 has OpenCL Option reinstated (which is high on the to do list) , the rendering speed will make Mandelbulber a very good choice.  (as the old Mandelbulber 1.21 OpenCL  still is.)  I would suggest wait for Mandelbulber V2.06, learn how to animate with it, then when V2.08? is released, switch to OpenCL rendering if you have a suitable GPU,  

What I need is free VirtualDub type program that can handle the png with alpha channel, does anyone know of such a thing?

Cheers

Yeah...  I am almost jealous of those whose brains can easily use Mandelbulber.  For some reason I just never got very far with it but still am determined to learn it if things ever calm down here!

As for free video editors that do layers and alpha and such, I remembered a promotion from the beginning of the year where Hitfilm Express was free, so looked it up :

It's still free, but there's a catch - you have to promote it on social media to get the link  

I'm one of those who avoid social media like the plague that I perceive it to be, so had to pass.  Here's the link if you are brave enough to use those sites : https://hitfilm.com/express/#download

Another option is just getting After Effects CS2 for free!  They listed the entire CS2 Suite with serial numbers when a crash caused them to lose the activation servers for that suite and said it was free for everyone at that point.

They quickly reversed course and said the downloads and serial numbers were only for people who bought the CS2 Suite.

I got mine before they changed the description so have a copy I feel is legal  (They can't change a user agreement after the fact, even for free software!), but with the new disclaimer your honor is all that is standing between you and a full, if slightly dated, adobe suite!  Since they now say it is not for everyone, I'll leave it to your search skills to find the links on adobe's site.  It's not hard to find.

Also - keep an eye on http://www.giveawayoftheday.com/ - they give away free licensed software every day, and sometimes nice video tools  

They converted to the "promote on social media model" to get things free as well, but offer a direct download if you give them your email

Hope that helps.