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Ma3rk
11-27-2014, 11:13 PM
Some months ago, I ran into a problem with some instanced geometry used with a spline to create tank like treads. I had some time this week to run test to try and isolate the issue and it seems to be strictly when using motion blur. This is with LW 11.6.2, Win 64.

While the treads are moving, the problem is either not there or at least not apparent. After they come to a stop though, the treads render intermittently or even “ghosted” where they are see through. (See attached).

I ran tests excluding the treads from radiosity thinking it might be some anomaly with GI but no change. Even thought the treads are polys, I also tried setting subdivision order to last and setting render subpatch to per polygon level. I even kicked up the number of MB passes. No help with any of that.

Only turning off MB does the problem go away which really isn't a solution as I want them to have blur. The only solution I can think of is to replace the spline instances with actual geometry.

Before I deem this a bug (and it is by most definitions), is there something not so obvious that I might check out first that could be causing this? The problem is repeatable, but doesn't repeat the same way on specific frames.

125726

djwaterman
11-27-2014, 11:50 PM
Warning Warning Will Robinson, looks like a bug to me.

sukardi
11-27-2014, 11:55 PM
Have you tried setting the instance mode to Parent instead of World or Local.

I don't really know how it works but when I have had problems with instances motion blur in the past when it was set to something other than parent.

Ma3rk
11-28-2014, 09:50 AM
Have you tried setting the instance mode to Parent instead of World or Local.

I don't really know how it works but when I have had problems with instances motion blur in the past when it was set to something other than parent.

Don't think so, so I'll certainly give that a try.

Ma3rk
11-28-2014, 10:25 AM
Have you tried setting the instance mode to Parent instead of World or Local.

I don't really know how it works but when I have had problems with instances motion blur in the past when it was set to something other than parent.

I'm not finding where you might change that.

In the Instances Panel tabs, everything defaults to Random however so I'm trying a sequence render test now with all set to Uniform.

M.

sukardi
11-29-2014, 02:50 AM
125737

This is what I mean...

Ma3rk
11-29-2014, 09:49 AM
125737

This is what I mean...

Ah yes. That. Been away from playing with instances for awhile.

Ya, ran test using parent and still has the problem. Defaulted to World & will try local just to be thorough.

Ma3rk
11-29-2014, 12:28 PM
Don't think so, so I'll certainly give that a try.

Tried all three options now and no luck.

Guess I'll contact someone official and see if they want to add this to something to check on in LW 2015 & if they want my scene to pick apart.

<sigh>

jeric_synergy
11-29-2014, 12:58 PM
??? "someone official"?? Why not just submit the scene thru the usual channels, ie FogBugz?

Also: "if"??? 8~

Ma3rk
11-30-2014, 10:39 PM
??? "someone official"?? Why not just submit the scene thru the usual channels, ie FogBugz?

Also: "if"??? 8~

Submitted it this evening finally but to [email protected] I'm trying to recall if I contacted them about this many months ago. I always have problems finding the right page with FogBugz for some reason.

If, as in I've no clue to their priorities, but curious if my motion blur thing might be related the 2015 issue that surfaced the first day of release.

jeric_synergy
11-30-2014, 11:06 PM
https://fogbugz.newtek.com/

Bookmark it. 8~

Ma3rk
12-01-2014, 11:26 AM
https://fogbugz.newtek.com/

Bookmark it. 8~

Gratzi!

Odd they don't just put that in with the docs.

jeric_synergy
12-07-2014, 03:09 PM
Gratzi!

Odd they don't just put that in with the docs.
Well, I can't speak to that, but there is also a new system where there's a reporting button on your account page. Look in the right column, it should be there.