Play It Forward - Revision history

Tkiesel: This deserves this categorization, I think.

2012-09-24T16:36:37Z

This deserves this categorization, I think.

Jdev: rename link

2011-11-17T12:30:37Z

rename link

Jdev: link to gradient PIF page added

2011-08-24T07:00:11Z

link to gradient PIF page added

Voidious: remove stub, add category=targeting

2011-04-05T18:57:22Z

remove stub, add category=targeting

Chase-san: /* Fast Play it Forward */

2010-08-01T02:53:29Z

Fast Play it Forward

Chase-san at 23:38, 31 July 2010

2010-07-31T23:38:25Z

Chase-san: Fleshing this out a bit.

2010-07-31T22:44:46Z

Fleshing this out a bit.

Voidious: stub definition

2010-04-28T20:31:27Z

stub definition

New page

{{stub}}

A method of generating a firing angle from a past situation. Using a log of enemy movements, one can "Play It Forward", simulating future movements, to determine where a bullet would have intersected the target bot.

Commonly abbreviated "PIF".

== See also ==

* [[DCBot]]

[[Category:Terminology]]

← Older revision		Revision as of 16:36, 24 September 2012
Line 28:		Line 28:
	[[Category:Terminology]]		[[Category:Terminology]]
	[[Category:Targeting]]		[[Category:Targeting]]
		+	[[Category:Advanced Targeting Strategies]]

@@ Line 24: / Line 24: @@
 * [[DCBot]]
 * [[Displacement Vector]]
-* [[PIF/Gradient PIF]]
+* [[PIF/Interpolating PIF]]
 [[Category:Terminology]]
 [[Category:Targeting]]

@@ Line 24: / Line 24: @@
 * [[DCBot]]
 * [[Displacement Vector]]
 [[Category:Terminology]]
 [[Category:Targeting]]

@@ Line 13: / Line 13: @@
 == Fast Play it Forward ==
-[[File:FastPIF0.png|thumb|right|252px|Original Locations and Recorded State.]]
+[[File:FastPIF0.png|thumb|right|252px|Current locations and Recorded state.]]
-[[File:FastPIF1.png|thumb|right|252px|Locations rotated and projected onto Recorded State.]]
+[[File:FastPIF1.png|thumb|right|252px|Current locations rotated and projected onto Recorded state.]]
 A faster version of the play it forward. It is faster since it skips the inner loop trigonometry calls usually done in the usual method. This method makes use of the stored location and heading. It is only beneficial when finding the end point is important, otherwise it may well be slower than the usual version. This is generally more confusing and complex to implement the first time around.
@@ Line 21: / Line 21: @@
 Then doing the reverse to get the final point. An simple optimization if only the angle is needed is getting the angle delta to the projected absolute angle, and applying it to the current one.
 == See also ==

@@ Line 16: / Line 16: @@
 [[File:FastPIF1.png|thumb|right|252px|Locations rotated and projected onto Recorded State.]]
-A faster version of the play it forward, method makes use of the stored location and heading. It is only beneficial when finding the end point is important, otherwise it may well be slower than the usual version. This is generally more confusing and complex to implement the first time around.
+A faster version of the play it forward. It is faster since it skips the inner loop trigonometry calls usually done in the usual method. This method makes use of the stored location and heading. It is only beneficial when finding the end point is important, otherwise it may well be slower than the usual version. This is generally more confusing and complex to implement the first time around.
 It requires rotating the battlefield around the location of the robot you are predicting. Rotating it so that the current heading would match the recorded heading. Then translating the entire field so that the current position equals the recorded position. This is because any other points on the field (such as another robots location), are subject to the current heading and location, rather then the recorded ones. Then playing it forward till you reach the wanted point. As usual with a Play it forward, a close match to the current heading difference and velocity are very important.

@@ Line 1: / Line 1: @@
 A method of generating a firing angle from a past situation. Using a log of enemy movements, one can "Play It Forward", simulating future movements, to determine where a bullet would have intersected the target bot.
@@ Line 25: / Line 23: @@
 * [[DCBot]]
 [[Category:Terminology]]

← Older revision		Revision as of 22:44, 31 July 2010
Line 4:		Line 4:

	Commonly abbreviated "PIF".		Commonly abbreviated "PIF".
		+
		+	== Play it Forward ==
		+
		+	The most common technique for playing it forward, is to store states of heading difference and the velocity. Some older robots used velocity delta instead, but this has the problem of bounds checking and less accurate outcomes.
		+
		+	With this technique, you take the current enemy location, heading, and velocity. Then for every state you want to simulate apply the stored states to the last one. They build on top of one another to build a simulated set.
		+
		+	== Fast Play it Forward ==
		+
		+	[[File:FastPIF0.png\|thumb\|right\|252px\|Original Locations and Recorded State.]]
		+	[[File:FastPIF1.png\|thumb\|right\|252px\|Locations rotated and projected onto Recorded State.]]
		+
		+	A faster version of the play it forward, method makes use of the stored location and heading. It is only beneficial when finding the end point is important, otherwise it may well be slower than the usual version. This is generally more confusing and complex to implement the first time around.
		+
		+	It requires rotating the battlefield around the location of the robot you are predicting. Rotating it so that the current heading would match the recorded heading. Then translating the entire field so that the current position equals the recorded position. This is because any other points on the field (such as another robots location), are subject to the current heading and location, rather then the recorded ones. Then playing it forward till you reach the wanted point. As usual with a Play it forward, a close match to the current heading difference and velocity are very important.
		+
		+	Then doing the reverse to get the final point. An simple optimization if only the angle is needed is getting the angle delta to the projected absolute angle, and applying it to the current one.
		+
		+

	== See also ==		== See also ==