Fog_Enviroment and Motionblur

[useruser]

hi everyone,
i have a problem with an actual project.
i need two things: a fog-enviroment and motionblur. both works separately without any problem but not together. in the attached (reduced)scenefile just enable the camera-motionlur in the cameratag and the fog disappers. is that a known limitation or an undiscovered bug?
i need both because of rolling wheels later in the animation, so post-motionblur in comp will not work. same for the fog-enviroment. its looks fantastic with octane and i cant reproduce the same look with depth-pass and compositing.

Fog_MotionBlur_Test.zip

(682.63 KiB) Downloaded 217 times

thanks a lot in advance!

[ChrisVis]

Hi Useruser,

I had a look at your scene file and fiddled around a bit with some shuttersettings and time shift in motion blur and couldn`t get it to work either, until I got the simple solution: Just enable all motion blur settings in the live viewer and "Full motion blur" in the Octane Render Settings.
You had only Camera Motion Blur activated, thats not enough, when the "Fog Volume" is moving itself with the camera.

Here the edited scene file:

Fog_MotionBlur_TestEdit.zip

(684.14 KiB) Downloaded 233 times

Cya,
ChrisVis

[useruser]

thank you ChrisVis!
the main problem i found out is that the object-tag in my complete scene does not transfer the "fog-sphere" to sceneviewer properly when i move through the timeline and when i disable/enable motionblur in cameratag. then the "fog-sphere" is gone. "send scenedata" again and the fog-enviroment is back. so both works together right now.

[useruser]

edit@
ok, to drag the "fog-sphere into the camera is the problem. it works now without any trouble if i use a PWG-Constraint-Tag on the sphere, parented to the camera.

[ChrisVis]

Hi useruser,

I also experienced the update lag on the live viewer... sometimes it was updated for a view frames, and suddenly it wasn`t anymore, then to resend the scene to octane helped. Not sure, if this also would happen in final animation render, with "resend only updated objects" is enabled.

Could you upload the updated scene?
This one would also be nice to share in the C4D Dropbox thread by martincarlson.
Maybe you remove your city geometry (if its from an actual project) and just add some blocks, to show the effect.

This would be a nice basic Fog Scene, that could be improved and added with other fog materials.

Cya,
ChrisVis

[aoktar]

There seems a problem with proper refreshing on LV with motionblur. Also don't use "after" option for motion blur. "After" and "Centered" options cannot work properly due the logic of caching system while playing. Just can work on first sent.

[ChrisVis]

Hi aoktar,

thanx for the clarification on how the shutter alignment should be used. I played around with this setting and just left it on after for some reason.

Now I did some more testing with the settings I posted above, thats what I experienced:

1. Shutter alignment set to "before"
I can scrub through the timeline forward without any problems, but as soon I jump back some frames, the fog and motion blur is gone. Going backwards some frames more, it stays the same.
If I then go forward a frame or more after that, its fine again. No need to resend the scene.

2. Shutter alignment set to "after"
It is the opposite way: When going backwards through the timeline, everything is fine, but If i scoll some frames forward after that, fog and motion blur is gone. Going backwards again, and it is fine again.

3. Shutter alignment set to "centered"
Gives the described effect randomly in both directions.

As you said, the logic of the caching system is going forward in play direction, so using "Before" is the right one.
So what are the shutter alignments "centered" and "after" are good for?
Any case, where to use them?

I didn`t test to render out the whole animation, but I think this problem is only when doing live preview, not final rendering.

Greetings,
ChrisVis

[aoktar]

honestly I'm not happy to talk about some secrets of plugin, but people should know some info to able work better. yes your tests are good and same info is available on manual. I could do more reliable system for interactive mode. but did not because of performance and obtain fast feedbacks.
objects are not located correctly due unavailable frames in caching when you jump to rand frames.

[ChrisVis]

Hi aoktar,

no need to go deeper into any secrets here. I just wondered, where this shutter alignment setting is for. In the manual (Version 2.1) I cannot find more information about it, thats why I asked.

But overall, I am very happy with the motion blur and I can live with the sometimes laggy motion blur preview in the live viewer, as long as it is rendered correctly in final rendering. So improve it, if you can or just leave it like this, its fine and I think most of us can work with it. And yes, performance is more important for live preview than accuracy here.

Previewing motion blur for animation in realtime is a big plus, so you already have done a very great job here!

Thanx again for your hard work.

Greetings,
ChrisVis

[aoktar]

Logic is simple modes:

Before: register the key frames before the current time as shutter length
After: register the key frames after the current time as shutter length
Center: register the key frames before and after the current time as half of shutter length

When you hit send the scene to LV, you can see the exact output. That's the way to be sure.