Proscene non-realtime camera interpolation

amnon.owed

Proscene non-realtime camera interpolation

in Contributed Library Questions • 1 years ago

I've been using Proscene and it's great. It's wonderful for creating camera paths. However I have some problems with sketches running/rendering at non-realtime framerates and the effect this has on camera interpolation. I went through all the examples and found two that were particularly interesting: Camera Interpolation and Frame Interpolation. To re-create the problem I'm having, add this line to the end of setup of either example:

frameRate(2); // to simulate a low framerate sketch

The original interpolation will look like this:

0 sec |-------|-------|-------|-------|-------|-------|-------|-------|-------| 1 sec

The slow framerate interpolation will look like this:

0 sec |------------------------------|--------------------------------------| 1 sec

This is not good, because when you put the frames back together in a movie, you are 'missing' a lot of frames. Now I understand from the reference that the interpolation is time-based, so it is in fact effectively doing it's job. However the endresult is not what I want. I would basically like something like the original, no matter how much time it took.

I found some very useful suggestions in this thread about slowing down the interpolation speed. This is a reasonable workaround. If the original framerate was 60fps and the rendering framerate is 2fps, then you can set the interpolation speed to 2/60 and I guess you end up sort of with the same endresult. However this is not an ideal solution.

I am wondering if it's possible to have camera interpolation based on frameCount instead of time, to make the camera movement independent of the rendering / sketch speed. Or are there other ways to use smooth interpolated camera paths under non-realtime conditions?

Replies(4)

nakednous

Re: Proscene non-realtime camera interpolation

1 year ago

Hi,

(sorry for the great delay getting back to you. I used to check the forum from time to time, but I didn't notice your question till recently)

You're right about your observation and the workaround. Proscene KFI is time-based since it uses java.util.timer. It's good for benchmarking purposes but it has its drawbacks: it's a bit awkward to fit a frame-based interpolation and each time an interpolation is started it runs on a separate thread (which is inherent to java util timers).

I was playing these days with some "single-threaded timers" which don't rely on java.util.*. Thus I will consider your issue to try to include them for a future release of the library.

Proscene animation mechanism, on the other hand, is frame-based. So maybe you can try to implement your interpolation code to use the animation mechanism. Please have a look at the different animation examples: Animation, AnimationHandler and Flock.

-jp

amnon.owed

Re: Proscene non-realtime camera interpolation

1 year ago

Thanks for your reply.

I have tried the animation examples, but alas I don't see how they can be of use for me in this project. I've ported a lot of my code to GLGraphics, which makes this project run in realtime. I'm also looking into ways to capture full HD output without slowing down the sketch. As long as everything runs realtime, the cameras work. It's really easy and fast to create camera paths, have automatic smooth interpolation between them and quickly switch from one to the other. So kudos for all those great features.

However the questions still stands, since there will be many cases where one wants and/or needs high-quality rendering which cannot be realtime. So I will wait and hope for a possible solution in a future release. This is one of my projects that is a little bit on the backburner for now anway.

I will continue to learn how to use Proscene. As said, it's very easy to make camera paths and switch between them manually in realtime. Now I want to learn how to use the created camera paths to build towards a combined 'cinematic master track' where the camera usage resembles to a certain degree the shots and editing of real movie cinematography. As I understand it there is a Scene which holds a Camera which holds keyFrameInterpolators (for different keys) which each hold Frames (which can be added, deleted, cleared). Are there ways to add all or some of the Frames from one kfi path to the 'master track'? What approach should I take to gain more control such as this over the kfi paths?

By the way, here is a geometry-intensive work-in-progress screenshot of the project.

nakednous

Re: Proscene non-realtime camera interpolation

1 year ago

to retrieve the frames from a kfi you can do something like this:

remixlab.proscene.Frame frame;
for(int index=0;index < kfi.numberOfKeyFrames();index++) {
frame = kfi.keyFrame(index);
//do whatever you want with the frame, e.g., collect it into an ArrayList for instance
}

if your master track is a kfi you can add the frames with one of the kfi.addKeyFrame methods.

As for the frame-based interpolation really want to see one of those geometry-intensive scenes animated ;) As I said, I have some experimental code. Maybe we can perform a collaboration to include it in your project and got a better feeling of the use-case before releasing it as an integral part of the library. What do you think?

amnon.owed

Re: Proscene non-realtime camera interpolation

1 year ago

Thanks for the kfi tips, they make sense.

My code is always experimental, so it sounds like a perfect match to test out some stuff.

You can find my email address here. If you have some code ready, I can test it. Right now it's a relatively small sketch. To make it more interesting I intend to introduce some order into the current chaos of form and color.

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