View Full Version : Photoreal Motion Blur - Bug or ID10T Error?

08-04-2013, 04:55 AM
So, this morning I felt a bit "spacey", so decided to have a play with my old Asteroid scene. I wanted to add a little motion blur, so decided to experiment with a few F9 renders to get the hang of it, but noticed a few things I wasn't expecting. Below are my results:


In order, they are no MB, 1 pass of Classic, 1 pass PR, 2 pass PR, and 3 pass PR. As you can see, the lower pass PR blurs produce a darkening of the image and visible artifacts. Is this a known issue with PR blur? Is it something to do with the mechanics of rendering that I'm unaware of? Is there a setting somewhere that I need to change to stop this happening? Should I Fogbugz this?

Rendered on 11.6 on OSX, if that makes any difference.

Thanks in advance.

08-05-2013, 09:44 AM

Sixty views and no-one has a clue? Looking like a bug then. :)

08-06-2013, 02:55 AM
FogBugzed. (https://fogbugz.newtek.com/default.asp?pg=pgPublicView&sTicket=64204_8c805u0h)

08-06-2013, 03:07 AM
Are you using a normal map? If so, is it imported in the right color space?

08-06-2013, 03:08 AM
No maps, all procedurals.

08-06-2013, 03:10 AM
What camera type you using, advanced?

08-06-2013, 03:17 AM
Standard Perspective with default settings. AA 2/4, AS 0.01/0.0 for the above images, but upping that doesn't make any difference. All default settings for MB apart from changing the passes.

08-06-2013, 03:48 AM
Is the asteroid moving fast? Perhaps the darkening is due to that?


08-06-2013, 04:01 AM
Not particularly fast, but I suppose it could be an issue. Once I've finished playing with this DP Part move scene I'm fiddling with at the moment I'll go back and have a look.

08-06-2013, 10:10 AM
Try it with one pass more more AA or AS to fill in the noise. I don't know if that's what the issue is or not.

08-06-2013, 10:28 AM
Unfortunately not, I dropped the AA/AS down for those renders above for speed, but higher values still showed the problem. Hopefully NT will have an answer once they get into work.