Development:AI Navigation - Revision history

Nikai: sp

2010-06-29T09:28:13Z

cracken at 04:38, 20 December 2006

2006-12-20T04:38:38Z

cracken at 07:39, 27 November 2006

2006-11-27T07:39:43Z

cracken at 07:02, 24 November 2006

2006-11-24T07:02:52Z

New page

At present the navigation routines are quite limited.

The files involved are flybywire.* and navigation.*

Problems with the current routines are:
They are unable to navigate(efficiently) in a ship that has 90% of it's thrust only available in the fowards direction.

A solution I am pursuing is a general system of implementing states...

moveTo(position, velocity, heading, angular_velocity, time)

where a valid argument would involve between one and all of the vector arguments, and optionally time.

--More to come--

[[User:cracken|cracken]] 23:02, 23 November 2006 (PST)

@@ Line 4: / Line 4: @@
 Problems with the current routines are:
-They are unable to navigate(efficiently) in a ship that has 90% of it's thrust only available in the fowards direction.
+They are unable to navigate (efficiently) in a ship that has 90% of its thrust only available in the forwards direction.
 A solution I am pursuing is a general system of implementing states...
@@ Line 19: / Line 19: @@
 A bezier can be of any order, cubic, quadratic, linear and I suppose, a single point.
-The deriviative of a cubic bezier (with respect to the parameter x) turns out to be a quadratic bezier. What's more is that the control points that define this bezier, are simply (p3 - p2, p2 - p1, p1 - p0), the second derivative of a cubic bezier turn out to be a linear bezier, where the control points are given by (p3 -2p2 +p1, p2 -2p1 + p0) (I'm sure you can see a pattern forming here, I think I'm missing out some constants here, don't care)
+The derivative of a cubic bezier (with respect to the parameter x) turns out to be a quadratic bezier. What's more is that the control points that define this bezier, are simply (p3 - p2, p2 - p1, p1 - p0), the second derivative of a cubic bezier turn out to be a linear bezier, where the control points are given by (p3 -2p2 +p1, p2 -2p1 + p0) (I'm sure you can see a pattern forming here, I think I'm missing out some constants here, don't care)
 If we set dx/dt = k . velocity (the change of the parameter with respect to time is directly proportional to the velocity of the ship), with a cubic bezier, the acceleration of the ship will be a linear value between p3 -2p2 +p1 and p2 -2p1 + p0, so, by forcing these values to be within the circle defined by the ship's maximum acceleration, it constrains the trajectory to the set of all possible trajectories. yay!.

← Older revision		Revision as of 04:38, 20 December 2006
Line 13:		Line 13:
	At present, a valid trajectory for a ship is limited only by the absolute acceleration, that is, the acceleration in any direction. A fairly reasonable trajectory to interpolate between two points, each with an associated velocity can be calculated using a cubic bezier, where the length of the control points is relative to the velocity at the point.		At present, a valid trajectory for a ship is limited only by the absolute acceleration, that is, the acceleration in any direction. A fairly reasonable trajectory to interpolate between two points, each with an associated velocity can be calculated using a cubic bezier, where the length of the control points is relative to the velocity at the point.

		+	[en.wikipedia.org/wiki/Bézier_curve It may help to read this page on wikipedia for more information on beziers]

		+	A cubic bezier, for the purpose of this, can be defined as a function with four static parameters (the four control points), and one parameter that varies from 0 to 1 (i'll refer to this as x). Bezier(p0, p1, p2, p3)(t), to use a python like syntax. Or bez = Bezier(p0, p1, p2, p3), bez(0) == p0, bez(1) == p3

−	[[User:cracken\|cracken]] 23:39, ~~26 November~~ 2006 (PST)	+	A bezier can be of any order, cubic, quadratic, linear and I suppose, a single point.
		+
		+	The deriviative of a cubic bezier (with respect to the parameter x) turns out to be a quadratic bezier. What's more is that the control points that define this bezier, are simply (p3 - p2, p2 - p1, p1 - p0), the second derivative of a cubic bezier turn out to be a linear bezier, where the control points are given by (p3 -2p2 +p1, p2 -2p1 + p0) (I'm sure you can see a pattern forming here, I think I'm missing out some constants here, don't care)
		+
		+	If we set dx/dt = k . velocity (the change of the parameter with respect to time is directly proportional to the velocity of the ship), with a cubic bezier, the acceleration of the ship will be a linear value between p3 -2p2 +p1 and p2 -2p1 + p0, so, by forcing these values to be within the circle defined by the ship's maximum acceleration, it constrains the trajectory to the set of all possible trajectories. yay!.
		+
		+	More to come, I'm not a writer :)
		+
		+	[[User:cracken\|cracken]] 20:38, 19 December 2006 (PST)

@@ Line 9: / Line 9: @@
 moveTo(position, velocity, heading, angular_velocity, time)
-where a valid argument would involve between one and all of the vector arguments, and optionally time.
+At present, a valid trajectory for a ship is limited only by the absolute acceleration, that is, the acceleration in any direction. A fairly reasonable trajectory to interpolate between two points, each with an associated velocity can be calculated using a cubic bezier, where the length of the control points is relative to the velocity at the point.
-[[User:cracken|cracken]] 23:02, 23 November 2006 (PST)