diff options
Diffstat (limited to 'indra/newview/llphysicsmotion.cpp')
| -rw-r--r-- | indra/newview/llphysicsmotion.cpp | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/indra/newview/llphysicsmotion.cpp b/indra/newview/llphysicsmotion.cpp index 15d39c231f..08d734ddac 100644 --- a/indra/newview/llphysicsmotion.cpp +++ b/indra/newview/llphysicsmotion.cpp @@ -44,7 +44,7 @@ typedef std::map<std::string, std::string> controller_map_t; typedef std::map<std::string, F32> default_controller_map_t; #define MIN_REQUIRED_PIXEL_AREA_AVATAR_PHYSICS_MOTION 0.f -#define TIME_ITERATION_STEP 0.1f +#define TIME_ITERATION_STEP 0.05f inline F64 llsgn(const F64 a) { @@ -491,12 +491,6 @@ BOOL LLPhysicsMotion::onUpdate(F32 time) // const F32 time_delta = time - mLastTime; - - // Don't update too frequently, to avoid precision errors from small time slices. - if (time_delta <= .01) - { - return FALSE; - } // If less than 1FPS, we don't want to be spending time updating physics at all. if (time_delta > 1.0) @@ -555,6 +549,18 @@ BOOL LLPhysicsMotion::onUpdate(F32 time) // Break up the physics into a bunch of iterations so that differing framerates will show // roughly the same behavior. + // Explanation/example: Lets assume we have a bouncing object. Said abjects bounces at a + // trajectory that has points A>B>C. Object bounces from A to B with specific speed. + // It needs time T to move from A to B. + // As long as our frame's time significantly smaller then T our motion will be split into + // multiple parts. with each part speed will decrease. Object will reach B position (roughly) + // and bounce/fall back to A. + // But if frame's time (F_T) is larger then T, object will move with same speed for whole F_T + // and will jump over point B up to C ending up with increased amplitude. To avoid that we + // split F_T into smaller portions so that when frame's time is too long object can virtually + // bounce at right (relatively) position. + // Note: this doesn't look to be optimal, since it provides only "roughly same" behavior, but + // irregularity at higher fps looks to be insignificant so it works good enough for low fps. for (F32 time_iteration = 0; time_iteration <= time_delta; time_iteration += TIME_ITERATION_STEP) { F32 time_iteration_step = TIME_ITERATION_STEP; |