Hmmm. Having solved the issue with 3d blur blurring objects to something that shouldnt be visible but was behind it (by moving them apart) I've now got a new problem. Without 3d motion blur, I get this: No Blur (jpg) With 3d motion blur (which I really want for this animation), I get this: Blur (jpg) The lightsaber is one of _dodger's and I'm using these settings on the blade: Settings The render settings are - 3d motion blur open 0, close 0.2 (any close setting gives the same result) displacement maps ticked and set at 1 raytracing on (bounces 2) shading rate 1.0 max texture 3000 pixel samples 3 post filter size 1 Does anyone know what I can do to have both the blade and 3d blur, because I'd really like to. If I can't I'm going to hav to animate the saber blade as a seperate object and add it to my video later (doing 2d blur or something). I'd rather not have to do that. Thanks in advance for any help!

I did a little experimenting and it looks like the transparency-values do not work properly when 3D motion blur is on. Don't worry, I found a way that will give you transparency and motion blur: Ray tracing. Here's an example material that will remain transparent when 3D motion blur is used. You will have to modify it a little for your needs (e.g. replace the spots node with your transparency map), but it should be a good start. You will need a higher number of ray trace bounces too. If you want to, you can set values other than 1 for the refraction index, that'll make the background appear warped around your light saber.

Adapting stewer's clever suggestion to _dodger's saber-blade prop ....

Genius! Thank you both for your excellent and speedy solution! This animation is going to look great :D

Let us know when it's finished, I love watching Poser animations!

My god, you people have an entire science to my lightsabre blades B^)