I have a series of .fph result files from a transient simulation, and I would like to create an animation/video to visualize velocity field evolution over time. How can I do this in the post-processor?
I have a series of .fph result files from a transient simulation, and I would like to create an animation/video to visualize velocity field evolution over time. How can I do this in the post-processor?
It's pretty straightforward to create an animation from transient results using the [Camera] object in scPOST. First of all, create your visualization of vectors on a [Plane] in the usual way, for any one of your FPH-files. Then follow these steps:
1. Open the dialog box for the [Camera] object. On the [Format] tab, select one of the movie formats; AVI, WMV, or MP4.
2. Use the [Browse] button to specify a folder and filename for the animation that you will create.
3. Still on the [Format] tab, click the [Start] button. This puts the camera on "standby"; any time the view in the Draw Window changes, a frame will be saved, for use in the animation.
4. Open the dialog for the [Main] object, which is just another name for the [FPH] files list. Go to the [Cycle] tab in that dialog.
5. Under [Cycle to Display], select the first cycle in the [Cycle] list, then click the [Set] button to update the Draw Window to that cycle number's results.
6. Check the box for [Automatic selection]. This will activate the icon that looks like a clock (to the right of the dialog, just under the [Step] setting.
7. Click on the clock icon. - scPOST will automatically step through the available cycles (FPH-files), updating the view in the Draw Window. You'll see confirmation in the Message Window that a frame is saved for each cycle.
8. Go back to the dialog for the [Camera] and click [End]. This will let scPOST know that you've saved all the frames you need. It will create an animation from the frames you saved and automatically play the animation using your default movie player.
There are a number of steps involved, but once you've been through them a few times it will become familiar. Here's an image illustrating steps 4 to 7:
Here are a couple of additional tips:
- It's best to use a fixed [Range] on your [Velocity] colorbar when you are creating an animation, so that the min/max limits don't change from frame-to-frame in the animation. In many cases, you can use the final FPH-file to help you decide the min/max range to use.
- In the [Camera] dialog, there are tabs for advanced settings for each of the movie formats. Here, you can make settings like [Frame rate], [Key frame] interval, and [Quality]. I often adjust the frame rate based on the number of FPH-files that I have, to make sure the animation has a good duration.
- Make sure you output FPH-files often enough to be able to create a meaningful animation. And if you're using a variable time-step, it's usually better to output your FPH-files using a fixed time interval rather than a fixed cycle interval.
One last thing: You can also create animations from a set of single-frame BMP-format images that you already have. This is done using the BMP2AVI tool. This is a more advanced topic, so I'll refer you to the "Advanced Guide to Postprocessor" document if you're interested in learning more. You can open that guide from the [Help] menu item in scPOST. Then search for "animation" and select [Animation Creation] from the list of hits.
