5 Replies Latest reply on Nov 2, 2015 9:59 AM by Rick Gerard

    beam effect doesn't support composition motion blur settings

    dsol21 Level 1

      I'm currently trying to build a Star Wars style Light saber effect in AE. I've got footage of an actor with a prop saber (just a white pole) and have tracked the hilt and tip (with the motion applied to two nulls).  I've set up a solid with the beam effect, with length set to 100% and used expressions to link the start and end positions to the nulls. This works great -  BUT - the motion blur doesn't match all my scene settings. It only seems to recognise shutter angle, not shutter phase. It also doesn't respect the number of samples settings (appears to be fixed at 8 samples)

       

      So (A) is there a workaround for this? perhaps using another plugin  -   and (B) how can I let Adobe know about this so the (ever so useful) beam effect can be updated to support this functionality?

       

      Many thanks to anyone who can help!

       

      Dan

        • 1. Re: beam effect doesn't support composition motion blur settings
          Rick Gerard Adobe Community Professional & MVP

          Motion blur is calculated on movement of layers for cameras. Pixels moving on the layers are not calculated with the standard motion blur so the option is to apply CC Force Motion Blur. This will work for any affect the causes pixels to move. It may require pre-composing the layer.

          • 2. Re: beam effect doesn't support composition motion blur settings
            dsol21 Level 1

            Thanks Rick, yes I'd tested using CC Force motion blur on it and it does work -  though sadly doesn't allow you to adjust shutter phase, to "align" motion blur with the footage I'm compositing with. It's also pretty slow (as it's a brute force approach). It would be really helpful if the beam effect was updated. I'll file a feature request.

            • 3. Re: beam effect doesn't support composition motion blur settings
              Rick Gerard Adobe Community Professional & MVP

              If I were trying to create like sabers  I would Roto over the prop using either shape layers or masks instead of trying to make the beam effect do the job. You can see through a solid  or a shape layer to tell what you're doing by changing the blend mode. Then you  adjust blur or feather and do a little color correction.

               

              My friend Alex Lindsay used to have a great tutorial on how to do this over at DV Garage.  It is gone now. I found this tutorial which is fair and will give you an idea of how to do it. His Roto technique is very amateurish as is his compositing. What I'm trying to say is there's a lot more efficient way to do it, but the principle is correct.  Given a better approach to Roto this can go very quickly and give you much more professional results than you could ever achieved using the Beam effect.

              Most of the light saber tutorials on YouTube are really awful. At least this one gives you a fairly decent look at a relatively effective technique.

              • 4. Re: beam effect doesn't support composition motion blur settings
                dsol21 Level 1

                Thanks for the ideas! The mask approach is OK - but doesn't give the curved edges on the tips you'd get with a real motion blur. However, I've found a pretty neat preset and tutorial by Andrew Kramer on videocopilot.net which seems like a decent approach: http://www.videocopilot.net/tutorials/light_sabers_v2/

                • 5. Re: beam effect doesn't support composition motion blur settings
                  Rick Gerard Adobe Community Professional & MVP

                  Matching the curved edges you get with real motion blur is precisely why I would use a mask. It's all about your Roto technique. Roto is how light sabers were done originally.

                   

                  Andrews preset is OK but you can get a lot better results using multiple copies of your actors and your light sabers, and it gives you the opportunity to make realistic clashes between the sabres. It does take a little bit more time and require a little bit more understanding of motion and perception.