How does A:M use percentages?

[bubba]

(This topic has been split off from another discussion.)

 

 

I would like to see a basic discussion first of how A:M uses percentages. I am of the old school that says a percentage is a fraction of something (and that 0 and 100 are the min and max.) So I would like to know the basis that A:M is uses for each property. Same for numbers. Some are easy like particle count or size (cm default but whatever the unit.) But velosity - is it furlongs per fortnight or what?

 

I know it is probably just me, but it would go a long way to helping me be a better animator.

[Rodney]

  Quote

I am of the old school that says a percentage is a fraction of something (and that 0 and 100 are the min and max.)

 

0 to 100 is a good way to look at percentages until you move beyond 100%.

How does old school deal with 101% or 200%, etc?

How do you deal with fractions such as 4/3 and 3/1?

[itsjustme]

  bubba said:

I would like to see a basic discussion first of how A:M uses percentages. I am of the old school that says a percentage is a fraction of something (and that 0 and 100 are the min and max.) So I would like to know the basis that A:M is uses for each property. Same for numbers. Some are easy like particle count or size (cm default but whatever the unit.) But velosity - is it furlongs per fortnight or what?

 

I know it is probably just me, but it would go a long way to helping me be a better animator.

 

I think most of these questions can be answered in the Technical Reference...which you can download here (15MB). Check pages 25-42 for Particle Systems...there are probably other pages with more information, but that's a good start.

 

Hope that helps.

[robcat2075]

What are some specific percentage units you have doubts about?

 

I'm not sure of the velocity units.

 

You could appraise this perhaps by setting up a simple emitter that gave off a few particles with no viscosity and no gravity and see how far they traveled and see if any relevant distance had been reached in 1 frame of 1 second (one second is the likeliest milepost since it depends not on frame rate.)

[Fuchur]

  robcat2075 said:

What are some specific percentage units you have doubts about?

 

I'm not sure of the velocity units.

 

You could appraise this perhaps by setting up a simple emitter that gave off a few particles with no viscosity and no gravity and see how far they traveled and see if any relevant distance had been reached in 1 frame of 1 second (one second is the likeliest milepost since it depends not on frame rate.)

 

In general, if I am not wrong, you are using the wrong setting.

If we are talking about sprites:

There are two possibilities to animate the velocity (and most other things):

- by the Sprite Emitter > no percentage value but a number for inital velocity.

- by the Particle System > percentage value of the underlying emitter-value.

 

The cool thing about the Particle System-properties: You can control many different sprite emitters without having to manipulate every single emitter-property by itself.

That would be much more redudant for lets say a Particle System with 20 emitters.

 

The percentage-value of the Particle System is based on the Sprite Emitter below it.

An example:

1. Sprite-Emitter > Initial Velocity = 100

2. Sprite-Emitter > Initial Velocity = 200

 

///////////////////////////////////////////////////////

So animated that would mean:

 

> Key 1: Particle System > Initial Velocity 100%:

Absolute: 1. Sprite-Emitter > Initial Velocity = 100

Absolute: 2. Sprite-Emitter > Initial Velocity = 200

 

> Key 2: Particle System > Initial Velocity 50%:

Absolute: 1. Sprite-Emitter > Initial Velocity = 50

Absolute: 2. Sprite-Emitter > Initial Velocity = 100

 

//////////////////////////////////////////////////////

 

I can't say which unit this "100 / 200" is so.

 

See you

*Fuchur*

[robcat2075]

unfettered particles, not under the influence of any force, and with no viscosity, appear to move 100 cm in 1 sec when velocity is set to 100

 

VelocityTester.prjFetching info...

 

[bubba]

  robcat2075 said:

unfettered particles, not under the influence of any force, and with no viscosity, appear to move 100 cm in 1 sec when velocity is set to 100

 

 

Then why not say "cms/sec" so that 100 would equal 100 cms per second.

 

Is Force based upon gravity so that a negative 1 in the minus-y direction a negative 1-G force?

[bubba]

  Rodney said:

0 to 100 is a good way to look at percentages until you move beyond 100%.

How does old school deal with 101% or 200%, etc?

How do you deal with fractions such as 4/3 and 3/1?

 

 

I would say (IMHO) that numbers larger than 100% would become factors, such as 2X or 3X; but they are still based upon a starting number - be it 1 or 100 or 1000. Or they can remain percentages - just need to know of what they are a percentage of. (sorry about the incorrect grammar.)

[robcat2075]

  bubba said:

Then why not say "cms/sec" so that 100 would equal 100 cms per second.

 

It could happen. To me the distances are so imaginary that not knowing the actual units never bothered me.

 

I don't know what happens if you switch A:M units to inches or feet. I suspect 100 will still mean 100cm.

[Fuchur]

I'd say, if you need it, write it down somewhere. I don't see any advantage in writing it 100 times at different places in the interface and making the interface less fun with that, because it gets such a technical look to it. In the end, it is not important anyway. Many 3d-animation-packages are not even having units like cm or inch. They just say 1 for one imaginary unit. It is always the proportain that matters, not the real unit. If a human is 1 (whatever unit) than a pencil should be about 1 / 15 (whatever unit) of him.

 

See you

*Fuchur*