home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
IRIX Base Documentation 1998 November
/
IRIX 6.5.2 Base Documentation November 1998.img
/
usr
/
share
/
catman
/
g_man
/
cat3
/
standard
/
bgntmesh.z
/
bgntmesh
Wrap
Text File
|
1998-10-20
|
5KB
|
133 lines
bbbbggggnnnnttttmmmmeeeesssshhhh((((3333GGGG)))) bbbbggggnnnnttttmmmmeeeesssshhhh((((3333GGGG))))
NNNNAAAAMMMMEEEE
bbbbggggnnnnttttmmmmeeeesssshhhh,,,, eeeennnnddddttttmmmmeeeesssshhhh - delimit the vertices of a triangle mesh
CCCC SSSSPPPPEEEECCCCIIIIFFFFIIIICCCCAAAATTTTIIIIOOOONNNN
vvvvooooiiiidddd bbbbggggnnnnttttmmmmeeeesssshhhh(((())))
vvvvooooiiiidddd eeeennnnddddttttmmmmeeeesssshhhh(((())))
PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
_n_o_n_e
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
Vertices specified between bbbbggggnnnnttttmmmmeeeesssshhhh and eeeennnnddddttttmmmmeeeesssshhhh are used to define a
mesh of triangles. The graphics pipe maintains two vertex registers.
The first and second vertices are loaded into the registers, but no
triangle is drawn until the system executes the third vertex routine.
Upon executing the third vertex routine, the system draws a triangle
through the vertices, then replaces the older of the register vertices
with the third vertex.
For each new vertex routine, the system draws a triangle through the new
vertex and the stored vertices, then (by default) replaces the older
stored vertex with the new vertex. If you want the system to replace the
more recent of the stored vertices, call sssswwwwaaaappppttttmmmmeeeesssshhhh prior to calling vvvv.
Between bbbbggggnnnnttttmmmmeeeesssshhhh and eeeennnnddddttttmmmmeeeesssshhhh you can issue the following Graphics
Library routines: cccc, ccccoooolllloooorrrr, ccccppppaaaacccckkkk, llllmmmmbbbbiiiinnnndddd, llllmmmmccccoooolllloooorrrr, llllmmmmddddeeeeffff, nnnn, RRRRGGGGBBBBccccoooolllloooorrrr,
sssswwwwaaaappppttttmmmmeeeesssshhhh, tttt, and vvvv. Use llllmmmmddddeeeeffff and llllmmmmbbbbiiiinnnndddd only to respecify materials
and their properties.
If you want to use bbbbaaaacccckkkkffffaaaacccceeee, you should specify the vertices of the first
triangle in counter-clockwise order. All triangles in the mesh have the
same rotation as the first triangle in a mesh so that backfacing works
correctly.
There is no limit to the number of vertices that can be specified between
bbbbggggnnnnttttmmmmeeeesssshhhh and eeeennnnddddttttmmmmeeeesssshhhh.
By default triangle vertices are forced to the nearest pixel center prior
to scan conversion. Triangle accuracy is improved when this coercion is
defeated with the ssssuuuubbbbppppiiiixxxxeeeellll command. Subpixel vertex positioning is
especially important when triangles are scan converted with antialiasing
enabled (see ppppoooollllyyyyssssmmmmooooooootttthhhh).
After eeeennnnddddttttmmmmeeeesssshhhh, the current graphics position is undefined.
EEEEXXXXAAAAMMMMPPPPLLLLEEEE
For example, the code sequence:
PPPPaaaaggggeeee 1111
bbbbggggnnnnttttmmmmeeeesssshhhh((((3333GGGG)))) bbbbggggnnnnttttmmmmeeeesssshhhh((((3333GGGG))))
bgntmesh();
v3f(v0);
v3f(v1);
v3f(v2);
v3f(v3);
endtmesh();
draws two triangles, (v0,v1,v2) and (v3,v2,v1), while the code sequence:
bgntmesh();
v3f(v0);
v3f(v1);
swaptmesh();
v3f(v2);
v3f(v3);
endtmesh();
draws two triangles, (v0,v1,v2) and (v0,v2,v3). There is no limit to the
number of times that sssswwwwaaaappppttttmmmmeeeesssshhhh can be called.
NNNNOOOOTTTTEEEE
On Impact and Infinite Reality llllmmmmccccoooolllloooorrrr cannot be called between bbbbggggnnnnttttmmmmeeeesssshhhh
and eeeennnnddddttttmmmmeeeesssshhhh
SSSSEEEEEEEE AAAALLLLSSSSOOOO
backface, c, concave, frontface, polymode, polysmooth, scrsubdivide,
defpattern, shademodel, subpixel, swaptmesh, v
PPPPaaaaggggeeee 2222