4/9/2024 0 Comments Flightgear scenery slowAs far as the FDM is concerned, it *is* running asyncronously, at a fixed time step. So our approach is intended to avoid that potential problem. One thing to keep in mind is that handing a different size time slice to the FDM every frame (and sometimes that time slice could be 1 second or more?) can lead to instabilities in the math. In the best case scenario, you've locked your graphics frame rate to 60 hz so the FDM runs exactly 2 iterations every time it is invoked and there is no temporal jitter at all, ever. This can produce a small amount of temporal jitter between the graphics and the fdm if the graphics frame rates are not a diviser of 120. Finally we save out the remainder and add that into the next time slice. We take the time that has elapsed since the last frame, compute how many whole iterations of the FDM will fit in that time slice (at 1/120th of a second per iteration.) Then we invoke the FDM that many times with a time step of 1/120th of a second. However, we play one small trick to make that happen. The FDM runs at 120 Hertz and with a fixed time step. This will only affect the speed of the simulation, not the local and UTC time. When running FlightGear at normal simulation rate /sim/speed-up is one. The aircraft will appear to fly /sim/speed-up times faster over the terrain. When the simulation is sped up and slowed down, the integer factor /sim/speed-up will increase and decrease. Neither simulation rate or time warp will affect for example the airspeed of the aircraft. The simulation rate affects how much faster or slower the FDM appears to run and the time warp affects how fast local and UTC time changes. Simulation rate and time warp manipulates the speed of the simulation and time in FlightGear. 3.1 Getting sub-second local and UTC time.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |