motion blur

V-Ray V-Ray for 3ds Max Issues
1

Hello friends !

I was reading almost every thread regarding vray motion blur.
But for some reason, I still have some troubles.

Here three frames:

a)
b)
c)

As you can see, the rim of the tire is sometimes with motion blur, sometimes without, and in one frame (ref.image b) I do have some weired artifacts. This is going through the entire animation. I think frame c looks ok, but I don’t know what happens with all the others.

I use Vray Cam Movie:
Shutter angle: 60

I also use the standard settings in the vray camera rolout.

What do I need to change to get that baby roll ?

thx for every little help,
bernhard

2

Is this 2d motion blur (looks like it)? If so, do you use the Motion blur render effect in 3ds Max or something else?

Best regards,
Vlado

3

uuahhhh

lol: you were absolutely right, I forgot to turn off the max 2d mb.

now it looks much better… just one additional question:
if I would like to have more blur, which parameter do I need to tweak ?

thx,
bernhard

4

If you use a VrayPhysical Camera, you need to adjust the shutter speed. Longer speeds = more motion blur. But it also makes the picture brighter so you have to compensate with aperture width or ISO. Oh by the way, longer speeds means SMALLER number :wink:
If you use perspective or a standard Max camera then you can adjust the motion blur in the VRay render settings. (duration)

5

hmm

allright, that all makes sense.

longer shutter speed = more motion blur

but what about the movie cam ?
we do have the shutter angle parameter, and all I could find in the manual and help file is this: Shutter angle - shutter angle (in degrees) for the cinematic camera.

Ok, I never worked with a movie cam, but on wikipeida I could find out that it works with frames, and that I already knew … hmm…

a) But what exactlty means now the shutter angle parameter in the vray camera settings ?
b) and how does it influence the motion blur ?

thank you for every little help,
bernhard

6

Here’s an explanation also covering motionblur :

http://en.wikipedia.org/wiki/Shutter\_angle

Regards,
Thorsten

7

yes

thank you, that was really a good link. I didn’t know that. great.

if I could understand that right, it means the following:

360 degree = full open, much motion blur
000 degree = closed, no light comes through the lens, no motion blur

ok, so only one vray parameter left I would like to understand:
the shutter offset deg

What does this parameter do and how does it effect the motion blur ?

8

hm. basically it shifts the angle. So it basically defines relative to the 3d max frame WHEN the shutter will open. So you can shift the mblur before or after your frame…i think at least :stuck_out_tongue: In the pic that would correspont to move the yellow bar within the frame interval.

Regards,
Thorsten