[BUG] Object Rotational Motion Blur

[Doug Armand]

There seems to be something wrong with object rotational motion blur.
I am trying to render a wind turbine with the props rotating.
The object centre is in the middle of the fan/blades and the rotation is on one axis only. There is no other rotation/location keys. But the renders are turning out a bit wierd as below.
Indigo 2.6.1 x64/Blender 2.49b x64/Blendigo 2.6.1.2/ Win64 x64

and you can download a blender file of this here
http://cid-abf95d459667e8f7.photos.live ... tion.blend

[OnoSendai]

Something weird going on there indeed.
How many animation keyframes are there? You will need at least three per revolution.

[Doug Armand]

Something weird going on there indeed.
How many animation keyframes are there? You will need at least three per revolution.

If by 3 you mean ones for XYZ? then yes Blender has put those in automatically.

For me I've just set 2 X Rotation keyframes. A keyframe on Rotation X of 0 at frame 0 and then another at frame 25 with some random X rotation - random because I'm animating a series of them and I'm just hand randomising the X rotation

I've then set the Rot X curve Interpolation mode to Linear and the Extended mode to extrapolation so they rotate like that forvever

it's probably something stupid that I'm doing but I can't see what - either way it would be nice to find a solution

[CTZn]

3, like 3 keys in time as a minimum (3 times xyz). That means that the rotation angle should not be too important, 120°-(rotation for one frame) sounding fine. e: then set the next keyframe by the same amounts.

That said my impression is just that the motion trail is following the Y axis, in Indigo space (the other horizontal axis than x in blender)

[dougal2]

The last changes to motion blur was when I added particle instance mb. I think ono is referring to min 3 keys in the exported data, I will check that is the case. However it really does look like x/y have got transposed

[dougal2]

Hi Doug,

I think this error occurred because your object has a local rotation and a keyframe rotation on top of that. I'm just trying to figure out the maths now to rotate the keyframes to match the object's local rotation.

[Doug Armand]

Hi Doug,

I think this error occurred because your object has a local rotation and a keyframe rotation on top of that. I'm just trying to figure out the maths now to rotate the keyframes to match the object's local rotation.

Not sure what all that means but I am glad your looking into it

[dougal2]

I'm not sure that meant anything at all.... still investigating. The problem goes away if I remove the -90 deg Z rotation

[CTZn]

Could it help to treat all rotations as keyframes, multiple or not ? Dunno if that's the case already.

Or check for a "keyframe rotation on top of" when writing meshes down so it comes transformed and ready to endorse the current keyframes ?

Screw the maths, dude

[dougal2]

Well, I ended up multiplying each keyframe transformation by the base transformation and it appears to work.
I altered the object to rotate about a non-axis aligned axis (+45 deg around Z) and it rendered OK:


(the text labels indicate the direction the camera is pointing).

I will make a release with this fix soon... after dinner

[dougal2]

Please let me know if 2.6.1.3 fixes this issue: http://www.indigorenderer.com/forum/vie ... 42#p102942

[Borgleader]

Well, I ended up multiplying each keyframe transformation by the base transformation and it appears to work.
I altered the object to rotate about a non-axis aligned axis (+45 deg around Z) and it rendered OK:

(flash video)
(the text labels indicate the direction the camera is pointing).

I will make a release with this fix soon... after dinner

By my understanding of things that would be the appropriate fix Such quick response time, ty dougal2!

[CTZn]

well done !

[Doug Armand]

Please let me know if 2.6.1.3 fixes this issue: http://www.indigorenderer.com/forum/vie ... 42#p102942

Excellent work Dougal - that seems to have fixed the problem.

BTW your video clip neatly displays the colour problem that Indigo GUI seems to have and that I mentioned as a bug here
http://www.indigorenderer.com/forum/vie ... =5&t=10422
but which some seem to think is by design.

[OnoSendai]

Such a cool picture!