[garin2]

hi

i'm trying get really long light trail effect.
i played with 'shutter' speed but the length of trail(object motion blur length) is always the same.



any idea how to increase the trail length?

[Lars Magnusson]

Hm, I don't have the ability to test motion blur ( don't have any of the plugin supported software like c4d, 3dsmax etc)

But according to a photography book I read...when doing night photography of cars, about 8 seconds exposure gives a good trail.
But that's for car speed....how fast is your doughnut moving?

[gotoxy av-media]

maxwell motionblur takes only +1/-1 frames into account...
so you have to fake it

munch

[Mihnea Balta]

Changing the shutter speed in Maxwell while it's rendering won't affect the motion blur. It would have to recompute the geometry and restart the render every time you move the slider. That shutter control only affects the exposure.

Change the shutter speed in the host application before exporting.

Also, Maxwell is currently limited to linear motion blur (it only considers the object position when the shutter opens and when it closes, and it assumes it moves on a straight line between those positions). You won't be able to render that curve you've set up in the host application.

[3dtrialpractice]

I would look into a composting solution to do this.. maybe with 3d plugin like trapcode Particular( red giant studio) plugins for after effects (or other compositors)
OR

if you use AfterEffects goto http://www.videocopilot.net and watch some of andrew kramer's FREE video tutorials on doing light streaks in AE..
(if you dont know.. Andrew makes THE BEST AE tutorials.. very engaging, smart, and entertaining on top of very versitile and informative tutorials.. did i mention FREE including project files most of the time... and if you dont know AE .. you can learn it from the ground up there using his BASIC TRAINING tuts...)


***EDIT:
you can import 3d cameras from maya, 3dsmax, and c4d (maybe blender) ionto AE too to get the composite exactly the same too

[ababak]

I'd better faked it with trail-shaped emitters in Maxwell rather than doing this in post-production.

[dariolanza]

Hello garin2,

This is a good question.

Motion blur on emitters is not implemented on Maxwell 2.5 yet.

Currently we are working an vast improvements in the motion blur routines, and this will be possible in the next update.

Meanwhile, I would suggest you to simulate that effect using the Motion Vector channel: enabling Motion Blur (on the Maxwell Render Settings) and enabling the Motion Vector channel exportation (in the Channels list) will export a buffer with the motion blur information (you will see it as a greenosh image) pear frame, that you can use in your post-production package to produce the directional blur effect (using the non-blurred render and the motion vector channel containing the direction and speed information).

The industry standard Motion Vector plugin for this purpose is ReelSmart Motion Blur.

Producing the motion blur effect in post using the Motion Vector channel is faster and easily adjustable (while not equally accurate).

Anyway, we are currently working on many improvements in the Motion Blur routines, that will include moving emitters and many other issues.

Let me know if this answers your question.

Greetings

[3dtrialpractice]

thanks for info NL!

currently we have a project using Airplane propeller blades and its rendered via maxwell.. all exept for the propeller as the motion blur on it doesn't look good..so we are faking that...
so this is great news that a future upgrade will have motion blur issues addressed!

[jfrancis]

By coincidence I'm trying to do showers of sparks with geometry emitter-instanced particles.

[jfrancis]

Now that we have long time frame emitter motion blur in Maxwell 2.6 has anyone any new ideas about these things?

I'm still experimenting with trying to make showers of parks pouring over objects by instancing emitter particles and it keeps crashing using that approach. Instanced emitters still not permitted, I guess?

I'd better faked it with trail-shaped emitters in Maxwell rather than doing this in post-production.

Still seems to be the best approach for what I'm doing, although it's not really feasible to model all the ricochets and bounces.

[Mihai]

It's a current bug with instanced emitters, that it's not inheriting the original objects material in case of emitter materials. But it will be fixed for the next update.

http://www.maxwellrender.com/forum/view ... 13&t=37610

What application do you use for creating the scene? So Maxwell crashes when rendering this? If you apply directly the emitter material to the instances does it work?

[jfrancis]

It's a current bug with instanced emitters, that it's not inheriting the original objects material in case of emitter materials. But it will be fixed for the next update.

http://www.maxwellrender.com/forum/view ... 13&t=37610

What application do you use for creating the scene? So Maxwell crashes when rendering this? If you apply directly the emitter material to the instances does it work?

From Maya 2012 to Maxwell the Maxwell app crashes after beginning voxellation, if I recall.

[jfrancis]

On particles directly:

ERROR: - Extension object nParticle1 has a emitter material applied. Extension objects do not support emitter materials yet.

[jfrancis]

On instances directly - a material is ignored.

On the initial object, a material is inherited.

---------

Unless the material is an emitter, in which case maxwell.exe soon crashes.