Generating Flowmaps in Terragen for animation of static skies.

[kvasibarn]

Hi!

I wonder if its possible to generate flowmaps (motion vectors) in TG4 to simulate cloud movement / wind on a static image.
[attachimg=3]
Using these colors

There have been some animated gifs of stormclouds literally circling the web lately showcasing the effect I am after.

[attachimg=2][attachimg=1]

Any ideas?

[cyphyr]

You could do something very similar without using flow maps, although I'm sure you probably could and I'd love to know how.
I made this a few years ago with transform and vortex shaders. I'll see if I still have the file (probably don't )

https://vimeo.com/134650275

EDIT: Tgd is a few posts down and I had previously uploaded it HERE.

[luvsmuzik]

You could do something very similar without using flow maps, although I'm sure you probably could and I'd love to know how.
I made this a few years ago with transform and vortex shaders. I'll see if I still have the file (probably don't )

https://vimeo.com/134650275

I have your 4DVortexLayer tgd?

[kvasibarn]

You could do something very similar without using flow maps, although I'm sure you probably could and I'd love to know how.
I made this a few years ago with transform and vortex shaders. I'll see if I still have the file (probably don't )

https://vimeo.com/134650275

That looks relly nice but it also looks like you had to render multiple frames? I am looking for a way to animate a single frame.

Cheers!

[cyphyr]

You could do something very similar without using flow maps, although I'm sure you probably could and I'd love to know how.
I made this a few years ago with transform and vortex shaders. I'll see if I still have the file (probably don't )

https://vimeo.com/134650275

I have your 4DVortexLayer tgd?

Could you re-upload it?
I don't seem to have it any more

[luvsmuzik]

Sure....I think this may have been a share, may still be there

[kvasibarn]

There is a Render Layer for 2D motion vectors. I wonder if that solves my problem... Trying it

[attachimg=1]

[kvasibarn]

Trying it, but I cant seem to get anything but 0/0/0 black in my Cloud 2D motion vectors, even though the clouds are animating.

Only way to get it to render something is to have an animating camera in the scene, but I think it would be great to be able to generate motion vectors for cloud movement as well.
@oshyan?

[attachimg=1]
(Camera animation cloud motion vectors)

https://realtimevfx.com/t/motion-vectors-for-animated-textures-how-do-you-generate-them/575/27
This thread has some juicy information.

[cyphyr]

Sure....I think this may have been a share, may still be there

Hey that's brilliant, thanks.
I never completed the full animation and this version is much longer than the one I posted on vimeo.

[Oshyan]

Motion Vector render element output probably has the same limitation that all Motion Blur does in Terragen: it only accounts for *camera* motion, not object, texture, shader, or displacement change.

- Oshyan

[kvasibarn]

Motion Vector render element output probably has the same limitation that all Motion Blur does in Terragen: it only accounts for *camera* motion, not object, texture, shader, or displacement change.

- Oshyan

I was afraid that was the case. I guess I can render out a few frames and generate the motion vectors in something like AE or Nuke.

thanks!

[ajcgi]

Indeed. I've always used ReelSmart for that in the past. The motion vectors for the ground work fine, but the clouds less so, ordinarily.

[cyphyr]

Forgive my ignorance but I don't see how you can animate a single frame. The gifs you have at the start of this thread are multiple frames compressed into a single image. They could equally have been turned into a mov or mp4 ...

[kvasibarn]

Forgive my ignorance but I don't see how you can animate a single frame. The gifs you have at the start of this thread are multiple frames compressed into a single image. They could equally have been turned into a mov or mp4 ...

Yeah, sorry, those gifs were not the best examples. It was the best I could dig up fast.

You can use motion vectors to blend between frames like shown in the following video:
https://www.youtube.com/watch?v=ZvJuTKn3Bnc

Its good because you can get a lot of mileage out of very low framerate material. Especially for realtime graphics.
You can even use motionvectors to blend a single frame and get quite realistic percieved motion from a static image. It will however result in some ghosting artefacts but its usually not too obvious.
https://youtu.be/XVkyV-GEbYI This video shows single frame animation of the skies in Starwars Battlefront I. Due to the speed up you can really tell its just one frame but you dont notice it as much at regular playback speeds.

If you had the option to generate motion vectors for clouds in terragen you would be able to cut rendering time for timelapses by a factor of 10. (Render every 10 frame and let the motion vectors blend between them).

[cyphyr]

Thanks for the explanation. Wow that's a really cool technique. That would be a great addition to Terragen, hopefully it will get picked up.