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royter
10-29-2009, 09:24 PM
i know that when working with dynamics, on has to set the playback speed to real time.
this is what i did for some falling particles but when i render at 24 fps (caching before rendering) they seem to fall faster when batch rendered , why is that? shouldn't the render animation be the same as the cashed simulation in the view port?

royter
10-29-2009, 09:32 PM
ok, i just discovered that it was because of my 3d motion blur.
how weird, motion blur is only suppose to mtion blur my particles, why is it speeding them?

TheRispo
10-29-2009, 09:32 PM
I suggest that before batch rendering you always do a playblast... the display in the viewport could be decieving... specially if is set to "play every frame -free" or "real-time" in any heavy scene

royter
10-29-2009, 09:37 PM
I suggest that before batch rendering you always do a playblast... the display in the viewport could be decieving... specially if is set to "play every frame -free" or "real-time" in any heavy scene

yes i know that ut it's not the case here.
when i render without motion blur th animation is faster.

TheRispo
10-29-2009, 09:37 PM
what are your motion blur settings?? perhaps the shutter oppening is too much??

ytse77
10-29-2009, 10:03 PM
i know that when working with dynamics, on has to set the playback speed to real time.


Actually should be set to "play every frame" so that maya doesn't skip any frames during dynamics calculations. To get a sense of the actual timing use playblast.

royter
10-29-2009, 10:20 PM
ok so whats the difference between those 2 methods:

simulate particles at "play every frame" speed / cahe simulation / render at 24 FPS

simulate particles at "24 FPS" speed / cahe simulation / render at 24 FPS

TheRispo
10-29-2009, 10:39 PM
the difference is in the viewport display.. the render is exactly the same..

If you set the playback speed to "real-time" maya will try to keep that frame rate, even if it didn't finished to do all the calculations for the sim.. so that could be a mess.
If you set it to "play every frame -free" maya will force itself to play trough every frame, thus allowing it to do complex calculations for each frame, and when its done, play the next.. this definetly does not give you close to real time playback speed.. If there is to little to calculate (a few particles just falling) maya will play every frame a lot faster than real time.
If set to "play every frame, Max real time" It will do almost the same as "play every frame- free" the difference is that if the calculations are simple maya will force it to play it real time.. (if the calculations are complex, it might be slower)

... anyway... always do a playblast every time before sending to render.. regardless of the settings of the playback speed.. Its the best to do

royter
10-30-2009, 03:26 AM
the difference is in the viewport display.. the render is exactly the same..

If you set the playback speed to "real-time" maya will try to keep that frame rate, even if it didn't finished to do all the calculations for the sim.. so that could be a mess.
If you set it to "play every frame -free" maya will force itself to play trough every frame, thus allowing it to do complex calculations for each frame, and when its done, play the next.. this definetly does not give you close to real time playback speed.. If there is to little to calculate (a few particles just falling) maya will play every frame a lot faster than real time.
If set to "play every frame, Max real time" It will do almost the same as "play every frame- free" the difference is that if the calculations are simple maya will force it to play it real time.. (if the calculations are complex, it might be slower)

... anyway... always do a playblast every time before sending to render.. regardless of the settings of the playback speed.. Its the best to do

with "play every frame", i get fluid\close to reality dynamics simulations that i can not achieve with 24 FPS wich seems always slow.
what's the ideal workflow when wanting to chieve realistic simulations?

pptc
10-30-2009, 04:17 AM
I thinks something wrong in setting, may be in global setting FPS set to 30fps (and playblasted), and when you compose at 24 it looking slow.

Or in playblast if you choose avi format - change playblast player to fcheck in his option and you can play with FPS speed by plus and minus keys on keyboard. Its show what actual fps on screen.

arkangel-fx
10-30-2009, 01:42 PM
with "play every frame", i get fluid\close to reality dynamics simulations that i can not achieve with 24 FPS wich seems always slow.
what's the ideal workflow when wanting to chieve realistic simulations?

Its not about realism or not. Dynamic simulations ALLWAYS have to be simulated using "Play Every Frame". In any other case if maya skips a frame while not being able to simulate it in real time, you'll get a wrong sim.

royter
10-30-2009, 03:27 PM
Its not about realism or not. Dynamic simulations ALLWAYS have to be simulated using "Play Every Frame". In any other case if maya skips a frame while not being able to simulate it in real time, you'll get a wrong sim.

but what's the use then of "play every frame" when you will render at 24 FPS?

TheRispo
10-30-2009, 03:43 PM
Ok... I'll try to explain..
Let's say you have a scene with a heavy fluid simulation, or tons of particles. There's a lot of calculation involved in order for maya to be able to handle that scene.. when you have your playback speed set to realtime, maya will try to display in the viewport the results of that calculation in realtime, independently if it finished doing the sim or not.. if maya can't handle the sim in realtime, as arkangel-fx already pointed out, you'll get a wrong sim.
That's why you should use "play every frame", this gives maya the opportunity to finish doing all calculations in one frame, before passing to the next frame.. this gives an accurate result, but is definetly not realtime display.. even if you make a disk cache, it will take some time for maya to read the cache data, and the results displayed in the viewport might not be in realtime..

Now... the final render will not be an accurate representation of the playback speed in the viewport and is independent of your playback speed settings, if you render in "real-time" or "play every frame" the image sequence will be exactly the same, the only thing that's diferent is in the viewport display.. That's why you should ALWAYS do a playblast before sending your scene to render.. to get an accurate representation of what the sequence will look like when rendered

royter
10-30-2009, 08:34 PM
Ok... I'll try to explain..
Let's say you have a scene with a heavy fluid simulation, or tons of particles. There's a lot of calculation involved in order for maya to be able to handle that scene.. when you have your playback speed set to realtime, maya will try to display in the viewport the results of that calculation in realtime, independently if it finished doing the sim or not.. if maya can't handle the sim in realtime, as arkangel-fx already pointed out, you'll get a wrong sim.
That's why you should use "play every frame", this gives maya the opportunity to finish doing all calculations in one frame, before passing to the next frame.. this gives an accurate result, but is definetly not realtime display.. even if you make a disk cache, it will take some time for maya to read the cache data, and the results displayed in the viewport might not be in realtime..

Now... the final render will not be an accurate representation of the playback speed in the viewport and is independent of your playback speed settings, if you render in "real-time" or "play every frame" the image sequence will be exactly the same, the only thing that's diferent is in the viewport display.. That's why you should ALWAYS do a playblast before sending your scene to render.. to get an accurate representation of what the sequence will look like when rendered

Ok so if i get it right, the best workflow would be to work with "play ever frame" play back speed with 24 FPS for its max limit. That way if its a simple simulation, it will playback at 24 fps just like playblast and rendred sequence.Now if its a complex simulation it will play slow (and thats normal because Maya is calculating the right simulation at each frame) and the only way to preview it in 24 FPS will be playblast. plz correct me if i am wrong.

TheRispo
10-30-2009, 08:49 PM
you get that right.. however is a good practice to always do a playblast... even if the display in the viewport looks like realtime.
Also make sure to use "play every frame, max realtime" this way if the simulation is too simple then maya will playback at realtime.

Have a nice day

royter
10-31-2009, 07:22 AM
thanks alot for the info!

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