Index buffer - Revision history

Tonyhilliam at 00:45, 18 January 2018

2018-01-18T00:45:43Z

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	[[Category:Modeling]]		[[Category:Modeling]]
	[[Category:Content creation]]		[[Category:Content creation]]
	~~[[Category:TRS18]]~~

Tonyhilliam at 03:57, 17 January 2018

2018-01-17T03:57:43Z

← Older revision		Revision as of 03:57, 17 January 2018
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	= Correlation with Polygons =		= Correlation with Polygons =
	As all [[Trainz]] geometry is built with triangles, there are exactly three indices per polygon.		As all Trainz geometry is built with triangles, there are exactly three indices per polygon.

	Where a [[mesh]] is built from higher-order polygons in the 3D modeling software, the polygons will be split into triangles either during the export process or the import process. This may lead to an increase in the number of polygons counted in the mesh, but does not lower performance. For performance analysis purposes, all polygon counts should be performed using triangles.		Where a [[mesh]] is built from higher-order polygons in the 3D modeling software, the polygons will be split into triangles either during the export process or the import process. This may lead to an increase in the number of polygons counted in the mesh, but does not lower performance. For performance analysis purposes, all polygon counts should be performed using triangles.

Tonyhilliam at 03:56, 17 January 2018

2018-01-17T03:56:50Z

← Older revision		Revision as of 03:56, 17 January 2018
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	= Impact on Performance =		= Impact on Performance =
	Index count is directly correlated with polygon count, which is one of the primary concerns when optimizing for performance.		Index count is directly correlated with polygon count, which is one of the primary concerns when optimizing for performance.

			[[Category:Modeling]]
			[[Category:Content creation]]
			[[Category:TRS18]]

Windwalkr: Created page with "An index buffer is a component of a render chunk which stores an array of indices. Each "index" is an integer which indexes into the corresponding vertex buffer. E..."

2017-10-13T09:59:22Z

Created page with "An index buffer is a component of a render chunk which stores an array of indices. Each "index" is an integer which indexes into the corresponding vertex buffer. E..."

New page

An [[index buffer]] is a component of a [[render chunk]] which stores an array of indices. Each "index" is an integer which indexes into the corresponding [[vertex buffer]]. Each triplet of indices in the index buffer defines a single [[polygon]] (also known as a "triangle" or "primitive"). This indirect technique allows multiple polygons to share vertices- this is a significant performance saving as a single vertex consumes far more memory (and memory bandwidth) than a single index, and a shared vertex only needs to pass through the vertex shader once.

= Correlation with Polygons =
As all [[Trainz]] geometry is built with triangles, there are exactly three indices per polygon.

Where a [[mesh]] is built from higher-order polygons in the 3D modeling software, the polygons will be split into triangles either during the export process or the import process. This may lead to an increase in the number of polygons counted in the mesh, but does not lower performance. For performance analysis purposes, all polygon counts should be performed using triangles.

= Impact on Performance =
Index count is directly correlated with polygon count, which is one of the primary concerns when optimizing for performance.