Triangle strip
triangle striped bikini tops, triangle stripe canvas 1999 mexican artworkA triangle strip is a series of connected triangles, sharing vertices, allowing for more efficient memory usage for computer graphics They are more efficient than triangle lists without indexing, but usually equally fast or slower than indexed triangle lists12 The primary reason to use triangle strips is to reduce the amount of data needed to create a series of triangles The number of vertices stored in memory is reduced from 3N to N+2, where N is the number of triangles to be drawn This allows for less use of disk space, as well as making them faster to load into RAM
For example, the four triangles in the diagram, without using triangle strips, would have to be stored and interpreted as four separate triangles: ABC, CBD, CDE, and EDF However, using a triangle strip, they can be stored simply as a sequence of vertices ABCDEF This sequence would be decoded as a set of triangles ABC, BCD, CDE and DEF then every evennumbered with counting starting from one triangle would be reversed resulting in the original triangles
Contents
 1 OpenGL implementation
 2 Properties and construction
 3 References
 4 See also
OpenGL implementationedit
Model of two triangles drawn in OpenGL using triangle stripsOpenGL has builtin support for triangle strips Fixed function OpenGL deprecated in OpenGL 30 has support for triangle strips using immediate mode and the glBegin, glVertex, and glEnd functions Newer versions support triangle strips using glDrawElements and glDrawArrays
To draw a triangle strip using immediate mode OpenGL, glBegin must be passed the argument GL_TRIANGLE_STRIP, which notifies OpenGL a triangle strip is about to be drawn The glVertex family of functions specify the coordinates for each vertex in the triangle strip For more information, consult The OpenGL Redbook3
To draw the triangle strip in the diagram using immediate mode OpenGL, the code is as follows:
//Vertices below are in Clockwise orientation //Default setting for glFrontFace is Counterclockwise glFrontFaceGL_CW; glBeginGL_TRIANGLE_STRIP; glVertex3f 00f, 10f, 00f ; //vertex 1 glVertex3f 00f, 00f, 00f ; //vertex 2 glVertex3f 10f, 10f, 00f ; //vertex 3 glVertex3f 15f, 00f, 00f ; //vertex 4 glEnd;Note that only one additional vertex is needed to draw the second triangle In OpenGL, the order in which the vertices are specified is important so that surface normals are consistent
Quoted directly from the OpenGL Programming Guide:
GL_TRIANGLE_STRIP
Draws a series of triangles threesided polygons using vertices v0, v1, v2, then v2, v1, v3 note the order, then v2, v3, v4, and so on The ordering is to ensure that the triangles are all drawn with the same orientation so that the strip can correctly form part of a surface
It's even more clearer within the manual pages4:
Draws a connected group of triangles One triangle is defined for each vertex presented after the first two vertices For odd n, vertices n, n+1, and n+2 define triangle n For even n, vertices n+1, n, and n+2 define triangle n N2 triangles are drawn
The above code sample and diagram demonstrate triangles drawn in a clockwise orientation For those to be considered frontfacing, a preceding call to glFrontFaceGL_CW is necessary, which otherwise has an initial value of GL_CCW meaning that triangles drawn counterclockwise are frontfacing by default5 This is significant if glEnableGL_CULL_FACE and glCullFaceGL_BACK are already active GL_BACK by default6, because backfacing triangles will be culled, so will not be drawn and will not appear onscreen at all7
Properties and constructionedit
It follows from definition that a subsequence of vertices of a triangle strip also represents a triangle strip However, if this substrip starts at an even with 1based counting vertex, then the resulting triangles will change their orientation For example a substrip BCDEF would represent triangles: BCD,CED,DEF
Similarly, reversal of strips’ vertices will result in the same set of triangles if the strip has an even number of vertices eg strip FEDCBA will represent the same triangles FED,ECD,DCB,CAB as the original strip However, if a strip has odd an number of vertices then the reversed strip will represent triangles with opposite orientation For example, reversal of a strip ABCDE will result in strip EDCBA which represents triangles EDC, DBC, CBA
Converting a general polygon mesh to a single long strip was until recently generally not possible Usually the triangle strips are analogous to a set of edge loops, and poles on the model are represented by triangle fans Tools such as Stripe8 or FTSG9 represent the model as several strips Optimally grouping a set of triangles into sequential strips has been proven NPcomplete10
Alternatively, a complete object can be described as a degenerate strip, which contains zeroarea triangles that the processing software or hardware will discard The degenerate triangles effectively introduce discontinuities or "jumps" to the strip For example, the mesh in the diagram could also be represented as ABCDDFFEDC, which would be interpreted as triangles ABC CBD CDD DDF DFF FFE FED DEC degenerate triangles marked with italics Notice how this strip first builds two triangles from the left, then restarts and builds the remaining two from the right
While discontinuities in triangle strips can always be implemented by resending vertices, APIs sometimes explicitly support this feature IRIS GL supported Swaps flipping two subsequent vertices in a strip, a feature relied on by early algorithms such as the SGI algorithm Recently OpenGL/DirectX can render multiple triangle strips without degenerated triangles using Primitive Restart feature
Referencesedit
 ^ http://developerapplecom/library/ios/#DOCUMENTATION/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/TechniquesforWorkingwithVertexData/TechniquesforWorkingwithVertexDatahtml
 ^ http://hacksoflifeblogspotcom/2010/01/tostripornottostriphtml
 ^ The OpenGL Redbook
 ^ 1
 ^ glFrontFace
 ^ glCullFace
 ^ OpenGL FAQ / 10 Clipping, Culling, and Visibility Testing
 ^ Azanli, Elvir Stripe, retrieved on March 28, 2007
 ^ Xiang, Xinyu FTSG, retrieved on January 21, 2011 link is no longer valid
 ^ Regina Estkowski, Joseph S B Mitchell, Xinyu Xiang Optimal decomposition of polygonal models into triangle strips In Proceedings of Symposium on Computational Geometry'2002 pp254~263 url=http://wwwamssunysbedu/~jsbm/papers/p151mitchellpdf url=http://portalacmorg/citationcfmid=513431
See alsoedit
 Triangle
 Triangle fan
 Computer graphics
 Graphics cards
 Optimization computer science
triangle stripe anne cole, triangle stripe art piece, triangle stripe canvas 1990s hispanic art, triangle stripe canvas 1999 mexican artwork, triangle stripe graphic design, triangle stripe rectangle quilt, triangle striped bikini tops, triangle striped red bathing suit top, triangle stripes, triangle strips
Triangle strip Information about

Triangle strip beatiful post thanks!
29.10.2014
Triangle strip
Triangle strip
Triangle strip viewing the topic.
There are excerpts from wikipedia on this article and video
Random Posts
La Porte, Indiana
La Porte French for "The Door" is a city in LaPorte County, Indiana, United States, of which it is t...Fernando Montes de Oca Fencing Hall
The Fernando Montes de Oca Fencing Hall is an indoor sports venue located in the Magdalena Mixhuca S...My Everything (The Grace song)
"My Everything" was Grace's 3rd single under the SM Entertainment, released on November 6, 2006 Unli...Turkish Straits
The Turkish Straits Turkish: Türk Boğazları are a series of internationally significant waterways in...Search Engine
Our site has a system which serves search engine function.
You can search all data in our system with above button which written "What did you look for? "
Welcome to our simple, stylish and fast search engine system.
We have prepared this method why you can reach most accurate and most up to date knowladge.
The search engine that developed for you transmits you to the latest and exact information with its basic and quick system.
You can find nearly everything data which found from internet with this system.
Random Posts
IP address blocking
IP address blocking prevents connection between a server or website and certain IP addresses or rang...Gisele Bündchen
Gisele Caroline Bündchen1 Portuguese pronunciation: ʒiˈzɛli kaɾoˈlini ˈbĩtʃẽj, German pronuncia...Sheldon, West Midlands
Sheldon is an area of east Birmingham, England Historically part of Warwickshire, it is close to the...Beverly, Chicago
Beverly is one of the 77 community areas of Chicago, Illinois It is located on the South Side on the...© Copyright © 2014. Search Engine