Enhanced controls for E&S Virtual Projector plugin for After Effects
What it does:
DomePath is a tool to enhance Evans & Sutherland’s Virtual Projector plugin for Adobe After Effects. Navegar Fulldome users: read on and you’ll find a link for a highly experimental and completely untested version for your evaluation. Please try it and send feedback!
Virtual Projector is a plugin used to place images on a planetarium dome master, warping the image so that it will look correct when projected on the dome’s curved surface. Input is in polar coordinates – elevation and azimuth. This is great for arranging images around the dome, but polar coordinates are limiting when it comes to animating:
By animating elevation alone, the image can go in a straight line from the horizon to horizon, through the zenith:
By animating azimuth, the image goes in circles around the zenith.
But what if you set keyframes at points A and B and animate between them? You won’t get the straight line you might expect! It’s not a bug, Virtual Projector is doing exactly what it’s told: animate azimuth and elevation as separate parameters.
So what if you want to animate straight-line paths or something more complicated?
DomePath helps by converting the cartesian (x-y) coordinates of an After Effects null object into the polar coordinates expected by Virtual Projector. Animate the motion of the null object any way you want, and Virtual Projector will follow along.
(Oh, that little rotational flip around the zenith? We can get rid of that with a setting. Read on.)
There are two After Effects scripts included: DomePath-v013-install.jsx, and DomePath-v013.jsx.
DomePath-v013-install.jsx only needs to be run once:
- Open After Effects
- In the General tab of AE’s Preferences, make sure “Allow Scripts to Write Files and Access Network” is checked. If you like, you can turn this back off after DomePath is installed.
- Select: File -> Scripts -> Run Script File…
- Navigate to and choose DomePath-v013-install.jsx
- Click “Install DomePath” (hey, what’s this installer thing doing?)
- Quit After Effects
While After Effects is not running, copy the other script, DomePath-v013.jsx, into After Effects’ Scripts folder:
/Applications/Adobe After Effects CC/Scripts/
C:\Program Files\Adobe\Adobe After Effects CC\Support Files\Scripts\
(Substitute your version of AE for “Adobe After Effects CC”)
Now, you can restart After Effects.
- Within your dome master comp, add an image into the timeline. This can be a simple image or movie file or a composition. (Note that Virtual Projector can not be applied directly to text or shape layers, but compositions containing these are fine.)
- Select the image layer in the timeline
- Select: File -> Scripts -> DomePath-v013.jsx
When run, the DomePath script adds Virtual Projector and the DomePath effect to the selected image. It also adds a new null object to the timeline, naming it after the selected image, plus the word “Control”. Now, your image is under the control of this null object.
Controlling your image with the Control Null Object:
The null object’s XY position controls the position of the image around the dome master.
The null object’s scale controls angular size of the image. 45% scale gives you 45 degrees width, for example. You can unlink horizontal and vertical scale to change the aspect ratio of the image.
The null object’s rotation property spins the image around its center.
The null object’s opacity controls the image’s opacity.
DomePath/Settings/Control Null Object
This selects the null object that DomePath will use to control Virtual Projector. A null object is automatically created and selected when the DomePath script is run, but you can select any layer to be your control… with a few caveats:
- By default, new null objects in AE have an opacity of zero, and DomePath passes the opacity of the null to the image. If you pick a different null object, don’t be surprised if your image suddenly disappears. Just turn up the null’s opacity.
- By default, a null object’s anchor point is at (0,0), which is different from most other kinds of layers. If your control layer’s anchor point is not (0,0), expect your image to rotate off-center.
- Don’t select the image layer itself to be the control layer. It won’t work.
This setting nullifies Virtual Projector’s normal behavior of aligning images with the horizon. This can be undesirable if you want something to fly straight past the zenith. With Rotation Control turned off, the image would flip unnaturally while passing near the center of the dome master. With this setting turned on, the image will maintain its rotation with respect to the composition.
With Rotation Control on, you can also make use of After Effects’ “Orient Along Path” feature. Select the control null in the timeline, and go to Layer -> Transform -> Auto-Orient…. With “Orient Along Path” turned on, the image will orient itself along on the path traced out by the null.
Whether Rotation Control is on or off, you can offset the rotation of the image by using the null object’s rotation property.
3D mode: If the control null object’s 3D switch is set, the width of the image will fall off (somewhat) appropriately with the Z-distance of the null object. The null’s scale value also still has an effect. Note that this 3D mode only affects the width of the image, and not its orientation in space.
When a null objects’ 3D switch is on, it gains extra rotation and orientation axes. Only the Z rotation will have any effect on the image.
The null object’s scale value still adjusts the width of the image, but the scale value now represents a percentage of size, rather than an absolute angular size, as in 2D.
I consider this somewhat experimental and under development. Mess around with it, see if it works for you, and let me know what you think.
Infrequently Asked Questions
Will this work with DomeFX or Navegar Foundation’s Fulldome plugin?
No, but I bet it would with a little tweaking. I don’t have access to either plugin, but someone kindly gave me an AE project that uses Navegar. So if ye be brave, download this zip file featuring DomePath-N for your evaluation and testing. Theoretically it should install and work just like the E&S version, but Navegar has a lot of extra features that I’m not familiar with, so please send feedback if you try it.
Hey, What did that installer thing do?
The effect “DomePath” is a “psuedo-effect,” just a regular old pile of expression controls, but compiled into a nice, neat, compact hierarchical structure by a cool script called Slim Expression Controls. For the “pseudo-effect” to show up correctly on your system, one of After Effects’ settings files must be edited, and that’s what the installer does.
To learn more about pseudo-effects, what they’re for, and how to make them ‘the hard way’, see the tutorial at batchframe.com/tutorials/12.
Hey, look at me, I’m writing up a change log! ::Dances around like someone who thinks he’s a software developer::
- Arbitrarily incremented version number by one, because generally stuff works better than the last time.
- Renamed “Target Null Object” setting to “Control Null Object” for clarity.
- Similarly, the automatically generated null object is now called “[layer] Control” instead of “[layer] Path”.
- Removed ‘rotate along path’ control. AE’s native Orient Along Path does the same job, and better.
- Height and width of image are now controllable separately by unlinking height and width of the control null object.
- It seems to be OK to open projects made with a previous version of DomePath, but not to mix versions in the same project. In fact, after opening a file with an old version, you’ll possibly have to restart AE in order to use the new version at all.
- Initial release. Randomly selected, low but non-zero version number.
It is possible that future versions of this will break compatibility with past projects you make with this. Other than that, these scripts probably shouldn’t doing anything bad… But install at your own risk. Eat your vegetables. Get some exercise. Visit your dentist. And make backups.