Liquid Motion Blur

   4264   8   1
User Avatar
Member
224 posts
Joined: April 2014
Offline
Does C4D correctly render motion blur from meshes that are being generated by an asset? I'm looking specifically at fluid meshes.

My guess/assumption is no, but I thought I'd check.
User Avatar
Member
12 posts
Joined: June 2006
Offline
If you are importing just the mesh data into Cinema4d then I don't think it will have any velocity data so motion blur won't render correctly. If you are using VDB I think it will have the correct data for motion blur…I'm not 100% sure on this though.
User Avatar
Member
345 posts
Joined: June 2008
Offline
although you can bring in velocity data using the vertex tag method, C4D's native renderers can't use it to render motion blur.
A third party renderer like Arnold could, in theory, use the data, but I have no idea if that is possible at the moment.
User Avatar
Member
224 posts
Joined: April 2014
Offline
Phooey. Figured as such. Most of my liquid work uses fast moving meshes, and motion blur is a necessity for realism. Real Smart Motion blur just doesn't cut it.

Really hoping that the Vray 3.xx update will be able to real velocity data from alembic caches (as 3Dsmax Vray does).
User Avatar
Member
76 posts
Joined: Jan. 2009
Offline
R17 will do it
Take look http://www.plugincafe.com/forum/forum_posts.asp?TID=11901&PID=47043#47043 [plugincafe.com]

for C++
  • -
    - New Motion Blur API
i'm sorry for my English
User Avatar
Member
345 posts
Joined: June 2008
Offline
Luke Letellier
…Real Smart Motion blur just doesn't cut it…

I have been brainstorming (by myself) and I think there's a possible solution.
Reel Smart uses a world velocity colour pass to extract the information needed.

You can feed the velocity attribute inside Houdini to a colour (Cd) attribute on your mesh and thus create a version of the meshed simulation that renders in colour. That colour (albeit with some calibration) would be a valid motion vector pass that RSMB uses to produce proper motion blur inside After effects.

As far as calibration, reading the Reelsmart FAQ:
http://revisionfx.com/support/faqs/motion_vector_FAQs/motion_vector_math/ [revisionfx.com]

Motion blur is calculated in screen space, so only Red and Green. I think the last entry (“Floating Point”) applies to our case.

I'll see if I can find a working solution, but any ideas are welcome.
User Avatar
Member
224 posts
Joined: April 2014
Offline
I was about to post something new here (see below) and just realized that I never responded to your comment. Doh! That's a great idea to try out if I had to. I'd really like to get legit 3D motion blur if I can, as 2D blur often leaves sneaky artifacts when you least want them, and you end up doing crazy workarounds to fix it…


Anyway, I made a post on the C4D plugin Cafe regarding R17's new motion blur SDK, and Karachi's comment sounds promising. Seeing as Maxon is in charge of development for the Houdini Engine plugin, do you know if they are planning to support liquid motion blur, seeing as they're the ones who created the new SDK?

http://www.plugincafe.com/forum/forum_topics.asp?FID=4 [plugincafe.com]
User Avatar
Member
345 posts
Joined: June 2008
Offline
Since I'm not a developer, I wouldn't know what this new API addition is for and to be honest, I just looked at the documentation and I have no idea what it's about :-)

Having said that, if we get point velocity Motion blur supported in C4D, then the velocity attribute from Houdini (3 vertex maps inside C4D) can be used for it, therefore (at least in theory) we will be able to render proper motion blur for fluids.

I'll post here if I have some news.
User Avatar
Member
224 posts
Joined: April 2014
Offline
noseman
I'll post here if I have some news.

Thanks!
  • Quick Links