Changing Frequency of Movie Capture

[GTRdrift34]

Hi, I am trying to get movie capture to run more frequently. I notice that it is run through the rmRedisplay() located in racerunningmenus.cpp. We are trying to get as many images as we can for research purposes. With my current setup (the default) i seem to be getting around 5 images a second- i would like to increase this to something like 100 images a second. I know that this will slow down the simulator significantly but this is not an issue for my study. Is there any way to improve movie capture frequency? Thanks.

[mungewell]

Did you check what the capture performance is like using a seperate application (ie. just grabbin screen content). "Record my Desktop" or the like.

If you have your replay system up and running, you could 'fake it' by replaying a drive at slower than life speed (using '+'/'-' keys) and setting back to normal in the editing process.

[GTRdrift34]

External capture works fine. I like the idea of faking the race by slowing down time but it is not the most ideal method. I managed to get replay to work, it basically updates the cars position according to the values i give it. My aim is to get a screen capture for everytime the position is updated but it seems to just freeze the screen at the loading race screen. I am calling the rmCapture() function from inside the SimUpdateCarPos() function in car.cpp..

[mungewell]

If you've got some code that you don't mind sharing you could post it as an attachment to the feature request....


We might be able to build on your work and include it in the main code.

[GTRdrift34]

Hi Simon i'll have to discuss the sharing of code with my supervisors it shouldn't be an issue.

Also it seems that slowing down the time to the minimal value seemed to give me my desired output of snapshots- i am getting something like 500 images for a 15 second run. I'm trying to develop a mathematical relationship between the simulator time speed and the number of .png files i am receiving. I think it is something trivial but i can't see it yet.

[mungewell]

Don't know if this works but in bug 500, JP suggested that there was a frame rate limiter,


It's enabled here:


You could select a rate that your machine can easily maintain and then use the 'slowed down time' trick to get a consistant number of rendered images.

Any luck getting the 'replay' code?
Simon.

[mungewell]

Just following up on this in case anyone is 'watching with anticipation'....

I now have a patch on the bug report which implements replay via writing sim state out to SQLite3 database during gameplay, this can be replayed by switching the sim engine to 'replay' and restarting the race.


There's a little demo here, last night's changes adds in the wheels and allows a field of robots to race.


Still a lot of tweaking to be done, and there is some concern whether SQLite3 is the best storage method - but it proves that's possible with minimal changes to code base. I'm hoping that this can be tuned enough to assist in producing a high quality promo video for the next release.
Simon

[mungewell]

Another little follow up.... Replay has progressed to the point where the playback looks almost identical to the original race, using the capture mode you can (moderately) easily generate a stack of PNG image. These can be stitched together at the right frame-rate and turned into a movie.

Little demo here:


Simon