How to Motion Blur ?

[cyprine]

i'm trying to take a single frame - in a (short) anim just there for the purpose of applying motion blur.
how do i acheive that ?

edit:
well, turns out that the camera autofocus seem to overide my manual setting. - is there a way to set the focus in animation rendering ?
anyways, i tried with only two frames out of the anim but projected time was far too long for 1 image (out of 2). so the question remains, is there a way for octane to apply motion blur on a single frame ?

edit2:
ok, seems i got my hand on it but... its only Camera motion blur - no object yet it seems.
a well, maybe next final patch ?

[linvanchene]

That "Object Motion blur" is not working in the current 2.23.2 version of the OcDS plugin now seems comfirmed from multiple sources.

- - -

OcDS specific:

It seems camera motion blur is working in animations.

- - -

Test scene:

Sphere at origin and moving camera from left to right.

Sphere static at origin.
Camera moving from left to right.

Frame 1 Camera at X -58 (center ball is on right side of image)
Frame 9 Camera at X 202 (center ball is on left side of image)

Bug or not?

I could not find a way to make camera motion blur appear when trying to render one frame of the animation in the default OcDS viewport.

Camera motion blur seems to only appear when clicking the "Start Animation" button in the animation tab of OcDS

To phrase this differently:
It seems impossible to actually preview camera motion blur in the OcDS viewport by scrolling through the timeline. Camera motion blur seems only to be calculated when the whole animation is rendered.

That does not seem like a very time efficent way to figure out the proper settings if the user has to render the whole sequence each time to know how the effect will look like at point x in time.


Is that a bug or just caused by the basic requirements of how camera motion blur is calculated in OcDS?

- - -

Side Note:

Assumptions:

- Object Motion blur: IF an object moves fast it gets blurred based on camera shutter speed and object movement speed
- Camera Motion blur: IF the camera moves the whole scene gets blurred based on camera shutter speed and camera movement speed.

Basically this would mean camera motion blur is used to simulate the effect of a moving or shaking camera.

- - -

[linvanchene]

To keep things separate I make a second post for this.
The following points may be general issues how motion blur works in OR.
Unfortunately since OR standalone does not have a timeline that would allow me to place keyframes for camera movement I cannot create a test scene to compare results.
So other users please add some feedback how it works in different plugins.

General Issues with camera motion blur and HDR backgrounds?


Test scene 2 - Camera Motion blur when translating the camera on the x axis:

Shutter Speed 1s

Shutter Speed 1/60s

Shutter Speed 1/1000s

- the sphere is static
- the ground plane is static
- the HDR background is static
- the only thing moving is the camera

Animation lenght 30 frames
X translation start at 7 frames
X translation end at 23 frames

In theory one would expect that the HDR background should also be blurred with camera motion blur and the showed section of the HDR background should change.

There are two parts to this observation:

- - -


- 1) No movement of the HDR background when the camera moves

This was to be expected based on how HDR backgrounds work when rendering still images.
If you translate the camera on one axis the background section shown stays the same.
If you rotate the camera then the shown section of the background will change.

workaround: manually translate (rotate) the background HDR to match the shift of the camera on one horizontal axis

An automated calculated solution in which the background shift in relation to the camera movement is calculated based on scene size might still be interesting.
.

Basically what seems missing is a toggle to select if the HDR background stays static independent of camera movement on one axis or is linked to it.

The other thing that seems missing is some values to define how far away the HDR background actually is from the camera.

If the background is very close like 10m away (interiors) the effect of horizontal or vertical camera movement should have a bigger effect on the shown section of the HDR background as if the HDR background is away 10'000m (landscapes).

At a distance of 10m a small x translation of the camera should have a huge effect on the HDR background section shown.
At a distance of 10'000m a small x translation of the camera may not have any visible effect.

- - -

- 2 ) No camera motion blur in the HDR background


As described above if the HDR background is about 10m away from the camera there should be very noticeable camera motion blur when the camera moves horizontally on the x axis.

But only when the background is very far away like 10'000m then it would make sense that the HDR background is not much blurred by horizontal camera movement on the x axis.

- - -

Can some of the administrators of OctaneRender standalone or other plugins share if this is a general limitation of OctaneRender or a plugin specific issue?

Any ideas or workarounds to get camera motion blur working with a HDR background?

Or did I simply overlook a toggle or button somewhere to activate this?
- - -

[linvanchene]

Case 3: Camera Rotation and Camera Motion Blur

Test Scene 3

groundplane static
sphere static
background HDR static
camera is rotating with sphere as reference point (aim at)

Animation lenght 30 frames
Rotation start at 7 frames
Rotation end at 23 frames
Shutter speed 1/250s

It seems when rotating the camera there is no camera motion blur at all?

No motion blur when camera is rotating?

Can some of the administrators of OctaneRender standalone or other plugins share if this is a general limitation of OctaneRender or a plugin specific issue?

Any ideas or workarounds to get camera motion blur with a rotating camera?

- - -

It would be very helpful if other people could share their results to figure out if it is just me doing things wrong or if what I observed is indeed the current state of camera motion blur.

Side Note:

Normally when there are issues I create a test scene in OctaneRender standalone to check how it works there.

But unfortunately OR standalone does not offer a timeline with editable keyframes.
So now I have no way to actually compare any results.

Therefore please users with access to other plugins add your input how camera motion blur works in your version of OR.