May 30 Daily Build and Motion Blur

[BigAl3D]

I have a scene that I need motion blur. This scene also used Cloners. Is there a known issue with motion blur and cloners? Before I post details, I want to make sure it's pointing out bugs in the daily build, or something bigger.

Also, is the stable B2 still available so I can compare the two?

[BigAl3D]

I made a quick video of stills showing my problem. When motion blur is enabled, it will randomly grab objects and place them floating above everything else. This video is me just clicking render to picture viewer several times. Nothing changed between renders, just the results. The Cloners I'm using are set to animate, so in other words, this project is an endless road. There is a group with one section of road, two street lights, a shoulder and the row of barriers. The car itself is only animated with a subtle vibrate tag and there is a camera move.

Notice that the barrier is never blurred, but when one is placed randomly, it is indeed blurred. Not sure if the road surface is being blurred properly. Hard to tell with that material.

If I turn off the motion blur options (I'm using Camera and Object), it will render perfect, minus not having any blur effect.


https://vimeo.com/282547207

[shane_w]

I have also had issues and reported it awhile back.  Post #68

https://forum.corona-renderer.com/index.php?topic=19743.msg125335#msg125335


Thanks,

-Shane

[BigAl3D]

Aha so the render instance setting strikes again. I had trouble getting my trees to properly appear on the surface of the land to the left and its clones. Render Instances was the cause.

Now the last thing that isn't working for me is the road and the shoulder don't seem to be responding to Object Motion Blur. Those objects are in the same group as the barrier and street lamps. Curious.

[Beanzvision]

Aha so the render instance setting strikes again. I had trouble getting my trees to properly appear on the surface of the land to the left and its clones. Render Instances was the cause.

Now the last thing that isn't working for me is the road and the shoulder don't seem to be responding to Object Motion Blur. Those objects are in the same group as the barrier and street lamps. Curious.

Care to share your scene with us? Uploader is in my signature ;)

[BigAl3D]

OK it's uploaded minus an HDRI called "cloud_layers_16k.hdr". It was free from HDRIhaven.com

https://hdrihaven.com/hdri/?c=skies&h=cloud_layers

[Beanzvision]

OK it's uploaded minus an HDRI called "cloud_layers_16k.hdr". It was free from HDRIhaven.com

https://hdrihaven.com/hdri/?c=skies&h=cloud_layers

No problem, I have them all. ;)

[grafichissimo]

I had the same problem, first animation no blur applied, second animation with blur you can see the evident issue.

PS The blur is applied in post with AE.

[BigAl3D]

Any updates on this issue?

[Beanzvision]

Is this still an issue? I wasn't able to reproduce it with the latest dailybuild 2018/09/25.

[Br0nto]

There are definitely some weird things going on re: motion blur and cloners. I have a rather complex grass-and-hills scene, where if I check the "object motion blur" option my road object starts to get really funky looking. In addition, random clones still lack motion blur frame to frame. I haven't gotten any crashes with motion blur lately though, so that's an improvement.

Overall I've been considering object motion blur broken for multiple builds now, and have only been using camera motion blur.

Attached are two renders: One with only camera motion blur on, the other with camera and object blur on. As you can see, as soon as object MB is enabled clones start losing textures, turning weird angles, and randomly missing MB as seen on one grass patch to the right.

Unfortunately I don't have time to simplify my scene, but I'll link it anyway. It has a similar setup to BigAl3D's endless road scene, just with more moving parts. It's also too large for the uploader, so I'll throw it on my google drive.
https://drive.google.com/open?id=18T32h3nVUBH2ew0IUJtWhN1NYaRqR6Vy

If indeed the issue is related to lots of items attached to a cloner, particularly one doing repetitive cycles on a spline, I don't know if simplifying the scene too much would defeat the purpose.

[houska]

Hi, we're working hard on the issue, but it's a non-trivial fix. It should be fixable though, so have patience :-)

In the meantime, I suggest turning off Render instances in the cloner. That should workaround most of the issues.

[Br0nto]

I very much appreciate your responsiveness and hard work. Thanks!

Unfortunately, turning off render instances makes this scene un-renderable on most of our computers, but it's good to know that's an option to avoid most of the problems temporarily.

[BLADE]

Hi, we're working hard on the issue, but it's a non-trivial fix.

Hopefully you don't rely on Maxon's motion blur calculations in any way. They can't do that with their physical renderer on render instances either. The error has been known there for years. From time to time there's some doctoring about it, but nothing useful comes out.

[BigAl3D]

@Blade Thanks for the reply. I did a test to see if what you say is true about C4D's motion blur issue, which I haven't seen myself. I replaced all the materials with a standard checkerboard C4D material. The cutout trees on the terrain are set to multi-instance. The result looks like the motion blur is working, is it not? See for yourself.

Cinema 4D R20.