Roku Developer Program

Join our online forum to talk to Roku developers and fellow channel creators. Ask questions, share tips with the community, and find helpful resources.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
EnTerr
Roku Guru

Re: Elastic Collision Ball Physics

"Romans_I_XVI" wrote:
Roku 3, if I do that on Roku 1 it's very laggy.

How many FPS on #42xx vs #3xxx vs 27xx?

Doing the elastic collision of round particles should be simple - admittedly i haven't done it in years but https://en.wikipedia.org/wiki/Elastic_c ... _Newtonian

The "pass trought" and "drag along" are interesting issues of simulation discretization to frames which i seem to vaguely remember. Your method of "back off" correction - does it work well when there is bunch of objects touching at the same time? For example line of balls like in Newton's craddle (no need of wires, end balls may bounce back from the room walls).

Alternatively, how about counting collision between two bodies only when they are touching (or overlapping) AND their speed vectors are colliding? (I.e. when they are pulling apart that's not collision or both are moving same direction and frontmost is faster, that's also not)
0 Kudos
Romans_I_XVI
Roku Guru

Re: Elastic Collision Ball Physics

Hey EnTerr, the "back off" method is working very well. I even added gravity and friction and the balls all eventually settled with no issues. 😄
0 Kudos
EnTerr
Roku Guru

Re: Elastic Collision Ball Physics

Well if you add enough friction, all issues will be settled sooner than later 😄
Looks quite neat, i share your enthusiasm!
W/o friction/gravity - it's a screen saver. With - it made me think of those sand picture frames - where you flip and watch sand grains settle down in water.

Don't you have something to track frames-per-second? I find it quite useful, but doing it right can be tricky. Here is what i do now (sorry for copying Lua, don't have my B/S handy but is trivial to adapt):
FPS_label = director:createLabel {
vAlignment = "top", hAlignment="right", textXScale = 2, textYScale = 2,
textBorderTop = 30, textBorderRight = 70, color = FONT_COLOR, zOrder = 100,
text = ''
}
scene:addChild(FPS_label)
avg_deltaTime = 0.03 -- start value, unimportant
time_to_next_report = 0
function update_fps()
avg_deltaTime = (19 * avg_deltaTime + system.deltaTime) / 20 -- keep running average
time_to_next_report = time_to_next_report - system.deltaTime
if time_to_next_report <= 0 then
time_to_next_report = 1 -- every 1 second
local fps = string.format(avg_deltaTime > 0.101 and '%.1f' or '%.0f', 1/avg_deltaTime)
FPS_label.text = fps
end
end
The interesting parts are keeping (exponential) moving average to stabilize the value - and updating the displayed text less often than every frame (for humane reasons)
0 Kudos
Need Assistance?
Welcome to the Roku Community! Feel free to search our Community for answers or post your question to get help.

Become a Roku Streaming Expert!

Share your expertise, help fellow streamers, and unlock exclusive rewards as part of the Roku Community. Learn more.