Motion Blur doesn't affect rendered Smoke Sim #25631

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Moolah Nasreddin · 2011-01-14T02:09:37+01:00

Moolah Nasreddin commented

2011-01-14 02:09:37 +01:00

Relates to: #21948

%%%WinXP 32bit Pro SP2, Blender 2.56a, 1683_34300

Unfortunatelly (as I did know that it's not good with reflections so I thought maybe it's the same nature of things) Vector Blur doesn't works with Volumetric materials.
So I did the smoke sim and decided to make a low-rez smoke with high contrast (in Texture settings) + Cubic B-Spline Interpolation which gives quite nice results even with low-res smoke. I did low-res as a compensation to render time to perform any motion blur (so with Sampled Motion Blur it's most be much slower with high-res simulation).
But Sampled Motion Blur don't want to render smoke's blur :) It gets only one frame. Seems that other objects renders normally.

Look the picture and try to render with my .blend.

P.S. The second picture shows the difference.

Thanks a lot for your hard work, guys!%%%

**Relates to**: #21948 %%%WinXP 32bit Pro SP2, Blender 2.56a, 1683_34300 Unfortunatelly (as I did know that it's not good with reflections so I thought maybe it's the same nature of things) Vector Blur doesn't works with Volumetric materials. So I did the smoke sim and decided to make a low-rez smoke with high contrast (in Texture settings) + Cubic B-Spline Interpolation which gives quite nice results even with low-res smoke. I did low-res as a compensation to render time to perform any motion blur (so with Sampled Motion Blur it's most be much slower with high-res simulation). But Sampled Motion Blur don't want to render smoke's blur :) It gets only one frame. Seems that other objects renders normally. Look the picture and try to render with my .blend. P.S. The second picture shows the difference. Thanks a lot for your hard work, guys!%%%

Moolah Nasreddin commented

2011-01-14 02:09:37 +01:00

Changed status to: 'Open'

Matt Ebb commented

2011-01-16 03:39:14 +01:00

%%%I edited the title of this report, since the problem is not in the volume rendering, it's in the smoke sim/cache. I havent checked the code lately, but I think the smoke sim / smoke point cache doesn't support sub-frame sampling - it will only give you the results for the current integer frame number. At the least it would be nice if even this just interpolated between frame N and N+1 depending on the fractional frame.%%%

Ton Roosendaal commented

2011-01-25 17:37:18 +01:00

%%%Assigning to Janne then!%%%

Janne Karhu commented

2011-01-26 12:52:21 +01:00

%%%There are actually two problems here. Unbaked cloth and softbody suffer from the first one too (bug #21948).

Unbaked physics and full sample motion blur can't work well together if the frame range used for the blur isn't cached (no way to interpolate the physics data). One solution could be to step the scene always a full frame forwards before rendering the blur samples between integer frames, but like I commented in the related bug the implications of this would first have to be investigated properly.
For cloth and sb baking will be enough to fix problem 1. as the data can then be interpolated between the frames just like Matt suggested, but currently smoke simulation isn't capable of any kind of interpolation even when baked. This would be very nice to have though at some point, so I'll add this as a todo-item to the wiki page http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Smoke.%%%

%%%There are actually two problems here. Unbaked cloth and softbody suffer from the first one too (bug #21948). 1. Unbaked physics and full sample motion blur can't work well together if the frame range used for the blur isn't cached (no way to interpolate the physics data). One solution could be to step the scene always a full frame forwards before rendering the blur samples between integer frames, but like I commented in the related bug the implications of this would first have to be investigated properly. 2. For cloth and sb baking will be enough to fix problem 1. as the data can then be interpolated between the frames just like Matt suggested, but currently smoke simulation isn't capable of any kind of interpolation even when baked. This would be very nice to have though at some point, so I'll add this as a todo-item to the wiki page http://wiki.blender.org/index.php/Dev:2.5/Source/Development/Todo/Tools#Smoke.%%%

Janne Karhu commented

2011-01-26 12:52:21 +01:00

Changed status from 'Open' to: 'Archived'

Janne Karhu closed this issue

2011-01-26 12:52:21 +01:00

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Motion Blur doesn't affect rendered Smoke Sim #25631