DELAY > Delaying Playback Speed to Achieve an Explicit Number of Frames/Second
DELAY > Delaying playback speed to achieve an explicit number of frames/second
By default an animation is replayed at the fastest speed that the computer can manage.
Sometimes, especially in animation mode, this can be too fast and some frames get skipped. Alternatively if you are running multiple D3PLOT sessions, and you want animations to proceed simultaneously in several windows, you may find that you need to set an explicit display rate to stop one process "racing" ahead of the others.
Therefore it is possible to specify how many frames per second are displayed using the preset definitions here, or by using the option to select any frame rate.
Limitations of controlling playback speed
On most computers it will be difficult to achieve controlled frame rates faster than about 60 frames per second since 60Hz tends to be the resolution of the average computer clock, and finer timing is not achievable.
In addition the refresh rate of your display is significant. Most liquid crystal displays (LCDs) run at 60 frames per second (60Hz), and typical cathode ray tube monitors at between 60Hz and 100Hz. Attempting to animate at rates faster than this not worthwhile, and can be counter-productive.
For small models it is possible that D3PLOT will deliver the frames at a rate faster than the display refresh speed, in which case one of two things will happen.
-
If the graphics adapter has "wait for vertical refresh
before swapping buffers" set then the animation rate will
peak at the display's refresh speed, giving good results. Signs
of this are smooth animation and the cpu usage of the D3PLOT process
dropping as it waits before swapping buffers.
This is the best outcome you can achieve and you need not take any action.
-
If the graphics adapter does not have "wait for vertical
refresh" set the results can be "tearing" between
successive frames as an image is redrawn part way through a buffer
swap and is thus made up of data from more than one frame.
If this occurs then you should turn on "Wait for vertical refresh" on your graphics adapter.
On Windows platforms this is usually achieved by and hunting through the options until you find the right setting.
On Unix / Linux platforms it is more difficult, and you may need to consult your hardware supplier for help.