On Friday 08 January 2010 20:51:18 Dahlia Trimble wrote: > I thought each terse update packet includes the sim time dilation at the > time the update was generated. Could this be used to scale the velocity to > slow the motion down? (if it's not already). May not help for network lag > but should help for heavily loaded sims. > > -Dahlia >
The time dilation is used in LLViewerObject::idleUpdate (llviewerobject.cpp starting at around line 1980.) every frame to interpolate velocity, position angular velocity, and rotation for moving objects. Maybe an optimization could be to factor in the sim's last known time dilation somehow together with the time dilation when the interpolated object last received an update (mTimeDilation)? I think the way it tries to compensate for the fact that the sim sends velocity averaged over the last sim frame is wrong. I think for the case of constant acceleration this would be wrong: LLVector3 delta_pos = (vel + (0.5f * (dt-PHYSICS_TIMESTEP)) * accel) * dt; (dt there is the time since the last viewer frame (compensated for sim time dilation). That doesn't make much sense to me, but maybe I'm missing something. A better way is to do: vel = vel + accel * (0.5f * PHYSICS_TIMESTEP * mTimeDilation) in LLViewerObject::processUpdateMessage. Also, note that ping interpolation doesn't do what it says it does (https://jira.secondlife.com/browse/SNOW-390 ) Thickbrick _______________________________________________ Policies and (un)subscribe information available here: http://wiki.secondlife.com/wiki/SLDev Please read the policies before posting to keep unmoderated posting privileges
