BFC - Revision history

Steffen at 15:15, 26 March 2024

2024-03-26T15:15:23Z

← Older revision		Revision as of 15:15, 26 March 2024
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	'''BFC''' is the abbreviation for <u>B</u>ack <u>F</u>ace <u>C</u>ulling.		'''BFC''' is the abbreviation for '''<u>B</u>ack <u>F</u>ace <u>C</u>ulling'''.

	That is a term from computer graphics:		That is a term from computer graphics:

Steffen at 19:22, 10 February 2024

2024-02-10T19:22:43Z

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	was tedious work. All of these corrected parts will be contained in the future official parts update, so that at some		was tedious work. All of these corrected parts will be contained in the future official parts update, so that at some
	point of the near future, a release will be done inside which ''all'' official part files are BFC certified.		point of the near future, a release will be done inside which ''all'' official part files are BFC certified.
	~~The Parts Tracker currently has a special page which lists all files it knows which are ''not'' BFC compliant:~~
	* http://www.ldraw.org/cgi-bin/ptbfcstatus.cgi

	=== New Parts ===		=== New Parts ===

Steffen: /* Counter-Clockwise and Clockwise */

2018-04-21T21:52:59Z

Counter-Clockwise and Clockwise

← Older revision		Revision as of 21:52, 21 April 2018
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	</pre>		</pre>
	into the header tells the consumer of this file that its contained triangles and quads follow the "CLOCKWISE" definition for "front" and "back".		into the header tells the consumer of this file that its contained triangles and quads follow the "CLOCKWISE" definition for "front" and "back".

			Ordering the points of a triangle or quad this way is called the "winding" of a triangle or quad.

	== Why is "Front" and "Back" Information of Surfaces Useful for Renderers? ==		== Why is "Front" and "Back" Information of Surfaces Useful for Renderers? ==

Steffen at 21:48, 5 April 2018

2018-04-05T21:48:35Z

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	New part authors should try to understand BFCing from the beginning.		New part authors should try to understand BFCing from the beginning.

	~~[[Category:Tutorials]]~~
	[[Category:LDraw Files Syntax]]		[[Category:LDraw Files Syntax]]
	[[Category:Terms]]		[[Category:Terms]]

Steffen at 17:37, 2 April 2018

2018-04-02T17:37:52Z

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	[[Category:Tutorials]]		[[Category:Tutorials]]
	[[Category:LDraw Files Syntax]]		[[Category:LDraw Files Syntax]]
			[[Category:Terms]]

Steffen at 12:45, 2 April 2018

2018-04-02T12:45:06Z

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	[[Category:Tutorials]]		[[Category:Tutorials]]
			[[Category:LDraw Files Syntax]]

Philo at 08:43, 28 March 2018

2018-03-28T08:43:06Z

← Older revision		Revision as of 08:43, 28 March 2018
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	[[Image:LDraw Design Pad - Change Winding Button.png]]		[[Image:LDraw Design Pad - Change Winding Button.png]]

			=== LD Part Editor ===
			[[LD Part Editor]] is a 3D + Text source editor for editing LDraw part files.
			Among its many possibilities it allows to highlight back faces and to change their orientation. I generally choose "Red backface" coloring (right click in 3D view window, then View Actions -> Red Backfaces). Less flashy than red/green mode, and it lets you properly see patterns on top surface. To change a face orientation, select it and click the "Swap BFC Winding" button or use the "J" keyboard shortcut.

			[[Image:Bfdldpe1.JPG]]

			You can also change orientation of selected lines in the text view using the same button, as shown below.

			[[Image:Bfdldpe2.JPG]]

	=== WINDZ ===		=== WINDZ ===
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	* Within the file, no switching between CCW and CW should occur.		* Within the file, no switching between CCW and CW should occur.
	* Writing 0 BFC INVERTNEXT should be avoided where possible, and only changing the sequence of corner points of triangles and quads should be preferred.		* Writing 0 BFC INVERTNEXT should be avoided where possible, and only changing the sequence of corner points of triangles and quads should be preferred.
	* Therefore, the only really useful purpose of the 0 BFC INVERTNEXT statement is to invert a primitive (for example, a torus segment).		* Therefore, the only really useful purpose of the 0 BFC INVERTNEXT statement is to invert a primitive (for example, a torus segment). Note that 0 BFC INVERTNEXT should not be used to invert flat primitives (eg. discs). Instead, mirror it across flat direction.

	== Status of the Official Parts Library ==		== Status of the Official Parts Library ==

Steffen: /* Status of the Official Parts Library */

2018-03-28T01:03:39Z

Status of the Official Parts Library

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	=== New Parts ===		=== New Parts ===

	New parts uploaded to the Parts ~~Tracked~~ should always strive to be BFC compliant from the beginning.		New parts uploaded to the Parts Tracker should always strive to be BFC compliant from the beginning.
	We do not want to re-start a phase of having to re-visit part files for their "BFC-fication".		We do not want to re-start a phase of having to re-visit part files for their "BFC-fication".
	New part authors should try to understand BFCing from the beginning.		New part authors should try to understand BFCing from the beginning.

	[[Category:Tutorials]]		[[Category:Tutorials]]

Steffen at 01:02, 28 March 2018

2018-03-28T01:02:43Z

← Older revision		Revision as of 01:02, 28 March 2018
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	* Therefore, the only really useful purpose of the 0 BFC INVERTNEXT statement is to invert a primitive (for example, a torus segment).		* Therefore, the only really useful purpose of the 0 BFC INVERTNEXT statement is to invert a primitive (for example, a torus segment).

			== Status of the Official Parts Library ==

			Much effort has been put into making ''all'' official parts BFC compliant, i.e., having properly oriented surfaces.
			Somewhere in January or February 2018, we reached the goal of correcting all currently official files, and submitting
			their BFC-corrected version to the [[Parts Tracker]]. Although not all of them are already certified to be contained
			in the next official parts release, this still is a major milestone, because looking into all parts and "BFCing" them
			was tedious work. All of these corrected parts will be contained in the future official parts update, so that at some
			point of the near future, a release will be done inside which ''all'' official part files are BFC certified.
			The Parts Tracker currently has a special page which lists all files it knows which are ''not'' BFC compliant:
			* http://www.ldraw.org/cgi-bin/ptbfcstatus.cgi

			=== New Parts ===

			New parts uploaded to the Parts Tracked should always strive to be BFC compliant from the beginning.
			We do not want to re-start a phase of having to re-visit part files for their "BFC-fication".
			New part authors should try to understand BFCing from the beginning.

	[[Category:Tutorials]]		[[Category:Tutorials]]

Steffen at 00:53, 28 March 2018

2018-03-28T00:53:47Z

← Older revision		Revision as of 00:53, 28 March 2018
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	~~<small>~~
	~~TODOs for this article:~~
	* add illustrative images
	* further elaborate the text
	* add a section which explains the effect of 0 BFC INVERTNEXT onto a referenced primitive in the next line
	~~</small>~~
	~~____________________________________________________~~





	'''BFC''' is the abbreviation for <u>B</u>ack <u>F</u>ace <u>C</u>ulling.		'''BFC''' is the abbreviation for <u>B</u>ack <u>F</u>ace <u>C</u>ulling.