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jeric_synergy
11-25-2012, 12:19 PM
I'm disremembering how to "preroll" a standard particle animation so that at frame zero some particles have already started to do their thing.

I realize you can bake out the particle motion, record an MDD, and preroll the MDD playback, but that's not very interactive, is it? :D

dwburman
11-25-2012, 02:41 PM
You simply need to click the Fixed box next to Start Frame on the Generator tab then enter a negative number for the Start Frame.

109370
http://forums.newtek.com/attachment.php?attachmentid=109370

jeric_synergy
11-25-2012, 03:26 PM
You simply need to click the Fixed box next to Start Frame on the Generator tab then enter a negative number for the Start Frame.

Thanks Dana.

?? Why is it "Fixed"?

Chrusion
11-25-2012, 04:42 PM
Fixed means you're making the sim/calcs start at a fixed, permanent time, like the photographic term of fixing a print in a fixer bath to make the developed image permanent.

Totally separate from the other "fixed" option, Fixed Random, which appears to use, again, the permanent, but randomly numbered vertex indexes to spawn particles. However, in this case the particles are spawned sequentially by vertex index number. Thus, if you created a mesh where vertices were physically created one after another in a row or column/row order, particles would be emitted one-by-one down the line or column/row like a long fuse linked to a matrix of fireworks mortars. Most meshes are not so neatly sequential with their vertices.

jeric_synergy
11-25-2012, 05:00 PM
Well, that doesn't make any sense to me: the START time is a global time parameter for the entire simulation, so the vertices as spawners seems neither here nor there, since they are spatial versus temporal.

IIRC there's a bunch of ill-named buttons in there: this is just one more. Not to mention the tab layouts-- thanks whoever layed that out, I love clicking endlessly. :P

Chrusion
11-25-2012, 06:07 PM
Didn't mean to confuse you with the Fixed Random stuff. IIRC, the Start Frame is grayed out until Fixed is checked. When unchecked, Start Frame is the same as the Timeline Start Frame. Enabling Fixed allows you to "bypass" the 'global anim time' so you can pre-roll or post-roll the sim without having to adjust the Timeline Start Frame.

jeric_synergy
11-25-2012, 06:40 PM
Oh, don't worry: just my usual rant about the UI really. Seems like misleading word is all. ;)

(Is that switch even NECESSARY? Why not just have it default to "0" or "1", and if the user changes the START FRAME, well, that's pretty self-explanatory. @^@ ) 8~

Then there's those "FX" boxes in some subsystem, don't even get me started.....

Mr Rid
11-25-2012, 08:10 PM
...

(Is that switch even NECESSARY? Why not just have it default to "0" or "1", and if the user changes the START FRAME, well, that's pretty self-explanatory. @^@ ) 8~

....

Correct. And why, oh WHY isn't there a start frame offset/shift for baked PFX, like there is for image and object sequences, Cloth, Soft, and Hard FX. There is much unintuitive UI goofiness and discontinutity that really should be streamlined.