3D Viewer rotation issues

Hi, sometimes when using the 3D Viewer plugin, I can’t seem to properly move the volume with the cursor. It behaves like the rotation anchor is somewhere far in the distance, while at other times it behaves as I would expect, with the rotation anchor in the middle of the volume. Is there a way to actively change this?

I have experienced the same… I haven’t got a clue what is the problem and would also like to know how to resolve it.

Does this happen after some particular alteration of the content of the 3D universe or a particular user interaction? What happens if you add another object to the scene when this happens?

Many of the UI controls are defined as some mutation/transformation on the “selected” content. I’m not sure that the selection is guaranteed to be automatically updated for advanced 3D Viewer API usage.

No idea, sorry. It seems to happen only sometimes and cannot determine what is the problem. I have no idea what happens if other objects are added because we only use single volumes (microCT volumes).
I noted that even the View>Centre> commands sometimes make no difference.
I know that my comment is pretty useless for debugging but at least I can confirm that there seems to be some kind of intermittent problem.

For me it seemingly behaves differently for different object sizes. I’m using it with ImageJ 1.51n.

Loading a smaller object always works fine. It’s a 400x400x120 grey level volume, displayed with standard settings. Movement when dragged with the cursor occurs around the center point and feels intuitive. Zooming works fine. The ‘x y z’-rulers stay in place.

I close the plugin and open it again to load a larger volume, about 2600x2000x120, again with standard settings. It looks fine at first (fig. 1) but I can’t properly rotate it with my mouse. As soon as I click on the volume, some digits displayed with the coordinate system suddenly grow huge (fig. 2). Clicking and dragging the volume results in awkward, counter-intuitive movement along some anchor point that’s hard to determine. Fig. 3 shows what the example looked like after I tried rotating it along the y axis, dragging it from left to right–it effectively came nearer. Zooming with the mouse wheel is very slow. Rotation by choosing “View->Start animation” works fine.
Something else I noticed is that during the loading time, it’s possible to click into the 3D Viewer and rotate the (empty) coordinate system itself. If I keep the mouse button pressed, the volume will eventually finish being loaded and I can rotate it together with the coordinate system, which works perfectly well and fast, zooming also works fine. But as soon as I let go, the coordinate system is fixed and upon trying to click and drag again, the weird behaviour described above sets in.

The viewer behaves the same each time I try both of these examples.

E: I just tried loading both objects into one scene. Oddly, they both keep their respective rotation behaviour. I recorded a short movie: https://www.dropbox.com/s/64swv4wef4n94x4/3D_viewer_movie.avi?dl=0

Fig. 1:

Fig. 2:

Fig. 3:

Hi all,

I mainly experienced this when I started with 16-bit images and let the 3D viewer change it to 8-bit. I would also check for correct scaling of the image or set this again under >image >properties…
Can’t explain it but sometimes solved the issue for me.

Hi there,

I see the same as the OP, but only when trying to rotate an individual object that is selected (enclosed in red box). I have tried adjusting the stack’s origin as specified in the image>properties dialog to no avail.

If I de-select the object by clicking then dragging the empty background, then the viewer will rotate the entire scene, and in this case it rotates as expected.

This might explain why some users only experience the issue with larger objects that fill the viewer. In this case it is difficult not to click on the object, and thus inadvertently select it, while dragging,

This might suggest that the apparently inconsistent nature of the weird rotation behaviour could be due to the difference between rotating individual objects versus the entire scene.

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You’re right! I had always tried just dragging the background without realizing that I can and must de-select the object first. This is a decent workaround, though it sometimes requires zooming out to find a piece of background to hold on to.

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Which reminds me of this:

Can we get a beard for 3D Viewer please?

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