Walking through an object

[shuom]

Hi. I'm looking to make a video with avizo. The material I am working with is bread. Since it is porous and very well interconnect, I would like to follow one of the pores by "walking" through it with the camera without change the zoom, just the location. I haven't any way to move the camera forward that isn't zooming. Thanks in advance for your help.

[mmarsh]

Hi Shuom,

The easiest way to "dolly" forward without zooming is to use the Seek button on the Viewer toolbar. This is the buttom fifth from the left at the top.

Click once on the Seek button and then once on where you want to take the camera. You can add this point to your camera path, and then repeat. (Note that Seek requires you to click on some geometry in your scene, any point, line, surface, etc will work. But you cannot use Seek to click on a volume rendering.)

Alternatively, you can use the zoom button to advance, and then type in the console "viewer setCameraNearDistance 1" This will effectively reset the camera position based on the current zoom.

Cheers,
Mike

[shuom]

Hi. Thanks for the response. The seeking seems to work decently, but it doesn't quite do what I want - ie: going straight forward. I can't get the setCameraNearDistance to change anything.

>viewer getCamera
viewer setCameraOrientation 0.657433 -0.0968865 -0.747258 3.5046
viewer setCameraPosition 358.571 576.801 317.07
viewer setCameraFocalDistance 117.264
viewer setCameraNearDistance 45.4573
viewer setCameraFarDistance 189.214
viewer setCameraType perspective
viewer setCameraHeightAngle 44.9023
>viewer setCameraNearDistance 1
>viewer getCamera
viewer setCameraOrientation 0.657433 -0.0968865 -0.747258 3.5046
viewer setCameraPosition 358.571 576.801 317.07
viewer setCameraFocalDistance 117.264
viewer setCameraNearDistance 45.4573
viewer setCameraFarDistance 189.214
viewer setCameraType perspective
viewer setCameraHeightAngle 44.9023

The middle mouse pan is very nice for moving left and right. I was wondering if there was a way to pan forward and backwards (I've been using viewer rotate 90 panning, and viewer rotate -90).

[mmarsh]

Hi,

Sorry about my previous post. I advised you to change CameraNearDistance, but I should have advised you to change CameraFocalDistance.

Since there is no forward/backward "panning" widget, the best way to get what you need, is to zoom forward. When you have maxed out the zooming, the CameraFocalDistance will be zero. You can reset by "viewer setCameraFocalDistance n" where n is some positive value. Try n=1.

Then you can continue to zoom.

I will ask the R&D team to investigate a user-interface option for forward/backward zooming.

Thanks for your interest. Let me know if I can offer any more help.
-Mike