Talk:Parabolic Shot - Revision history

Genete at 23:22, 27 December 2007

2007-12-27T23:22:24Z

Dooglus at 20:43, 27 December 2007

2007-12-27T20:43:10Z

Dooglus at 20:42, 27 December 2007

2007-12-27T20:42:55Z

Genete at 15:20, 27 December 2007

2007-12-27T15:20:28Z

Genete at 15:17, 27 December 2007

2007-12-27T15:17:49Z

Genete at 15:15, 27 December 2007

2007-12-27T15:15:28Z

Genete at 15:06, 27 December 2007

2007-12-27T15:06:58Z

Genete at 15:01, 27 December 2007

2007-12-27T15:01:39Z

Genete: Parabolic shot with damping forces.

2007-12-27T14:55:11Z

Parabolic shot with damping forces.

New page

I'm trying to implement the equations for a parabolic show with small damping forces (the ones that exists when the projectile is shot in the air)

The equations are those:

<math>X(t) = X_0 + \frac {V_{0x}} {b} \left(1- e^{-bt} \right)</math>

← Older revision		Revision as of 23:22, 27 December 2007
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	-- [[User:Dooglus\|dooglus]] 15:43, 27 December 2007 (EST)		-- [[User:Dooglus\|dooglus]] 15:43, 27 December 2007 (EST)
		+
		+	Thank you very much dooglus. --[[User:Genete\|Genete]] 18:22, 27 December 2007 (EST)

← Older revision		Revision as of 20:43, 27 December 2007
Line 66:		Line 66:
	else		else
	return 1.0f / link;		return 1.0f / link;
		+
		+	-- [[User:Dooglus\|dooglus]] 15:43, 27 December 2007 (EST)

← Older revision		Revision as of 20:42, 27 December 2007
Line 50:		Line 50:

	Would it be possible to implement the "Inverse" convert type? --[[User:Genete\|Genete]] 10:17, 27 December 2007 (EST)		Would it be possible to implement the "Inverse" convert type? --[[User:Genete\|Genete]] 10:17, 27 December 2007 (EST)
		+
		+	I've added it, like this:
		+
		+	*<param> "Link"
		+	*Real "Epsilon"
		+	*Real "Infinite"
		+
		+	with this logic:
		+
		+	if (abs(link) < epsilon)
		+	if (link < 0)
		+	return -infinite;
		+	else
		+	return infinite;
		+	else
		+	return 1.0f / link;

@@ Line 45: / Line 45: @@
 Infinite is a very big value that represent a division by a small number smaller or equal to Zero.
-Zero is the smaller value that can be inverted. If Link<=Zero then it returns Infinite. Zero is not allowed to be 0.0. The convert type should limit it to a small value given internally by the code.
+Zero is the smaller value that can be inverted. If abs(Link)<=Zero then it returns Infinite. Zero is not allowed to be 0.0. The convert type should limit it to a small value given internally by the code.
 Otherwise it returns 1/Link
 Would it be possible to implement the "Inverse" convert type? --[[User:Genete|Genete]] 10:17, 27 December 2007 (EST)

@@ Line 1: / Line 1: @@
 I'm trying to implement the equations for a parabolic show with small damping forces (the ones that exists when the projectile is shot in the air)
@@ Line 27: / Line 29: @@
 <math>Y(t)=Y_0-\frac{1}{2}\cdot G \cdot t^2 + V_{0y}\cdot t</math>
-Implement in synfig one or other equation is quite easy using the Switch convert type. Other thing is implement the first group of equations.
+Implement in synfig one or other equation is quite easy using the [[Convert#Switch|Switch]] convert type. Other thing is implement the first group of equations.
 As well as the parameter b is dividing and multiplying at the same time there are only one possible solutions to implement that with the current synfig convert types possibilities: That the user enter the value of b and the value of 1/b into two separated parameters.
@@ Line 46: / Line 48: @@
 Otherwise it returns 1/Link

← Older revision		Revision as of 15:15, 27 December 2007
Line 32:		Line 32:

	To avoid that I'm asking for a "Inverse" convert type. It should have following sub - parameters:		To avoid that I'm asking for a "Inverse" convert type. It should have following sub - parameters:
		+
		+	*<param> "Link"
		+	*Real "Zero"
		+	*Real "Infinite"
		+
		+	Where:
		+
		+	Link is the parameter to be inverted: It can be a Real number only.
		+
		+	Infinite is a very big value that represent a division by a small number smaller or equal to Zero.
		+
		+	Zero is the smaller value that can be inverted. If Link<=Zero then it returns Infinite. Zero is not allowed to be 0.0. The convert type should limit it to a small value given internally by the code.
		+
		+	Otherwise it returns 1/Link

← Older revision		Revision as of 15:06, 27 December 2007
Line 20:		Line 20:

	and <math>V_{0x}</math>, <math>V_{0y}</math>, <math>X_0</math> and <math>Y_0</math> are the initial conditions for velocity and position.		and <math>V_{0x}</math>, <math>V_{0y}</math>, <math>X_0</math> and <math>Y_0</math> are the initial conditions for velocity and position.
		+
		+	If c=0 (no damping forces) the original differential equations are different and its integration gives other equations:
		+
		+	<math>X(t)=X_0 + V_{0x}\cdot t</math>
		+
		+	<math>Y(t)=Y_0-\frac{1}{2}\cdot G \cdot t^2 + V_{0y}\cdot t</math>
		+
		+	Implement in synfig one or other equation is quite easy using the Switch convert type. Other thing is implement the first group of equations.
		+
		+	As well as the parameter b is dividing and multiplying at the same time there are only one possible solutions to implement that with the current synfig convert types possibilities: That the user enter the value of b and the value of 1/b into two separated parameters.
		+
		+	To avoid that I'm asking for a "Inverse" convert type. It should have following sub - parameters:

← Older revision		Revision as of 15:01, 27 December 2007
Line 4:		Line 4:

	<math>X(t) = X_0 + \frac {V_{0x}} {b} \left(1- e^{-bt} \right)</math>		<math>X(t) = X_0 + \frac {V_{0x}} {b} \left(1- e^{-bt} \right)</math>
		+
		+	<math>Y(t) = Y_0 + \frac {1} {b} \left( \frac {G} {b} + V_{0y} \right) \left( 1-e^{-bt}\right) - \frac {G} {b} t</math>
		+
		+	Where:
		+
		+	t = the current equation time
		+
		+	b = c/m
		+
		+	c = the damping coefficient
		+
		+	m = the projectile mass
		+
		+	G = the gravity acceleration
		+
		+	and <math>V_{0x}</math>, <math>V_{0y}</math>, <math>X_0</math> and <math>Y_0</math> are the initial conditions for velocity and position.