Quote from: HELP FILEThe "back" is defined as the side of an object that its normal vector is not pointing to. The normal for every triangle in a 3d object is calculated automatically by the graphics engine. When you create a triangle, by drawing its points in an anti-clockwise direction you are telling the graphics engine to point the normal towards the camera rather than away from it.
X_OBJSTART 1
X_OBJADDVERTEX 0, 0, 0, 0,0, RGB(255,255,255)
X_OBJADDVERTEX -20, 40, 0, 0,0, RGB(255, 0, 0)
X_OBJADDVERTEX 20, 40, 0, 0,0, RGB( 0, 0,255)
X_OBJEND
This is quoted from the help file....
In this excerpt the document says must be drawn anti-clockwise, which is counter clockwise i believe.
But the vertex are written in the sample below moving in a clockwise motion.
Should it be drawn clockwise or counterclockwise?
Is cullmode reversed?
Or is the documentation worded wrong?
the vertices here are drawn counter clockwise ;)
Hmm, whats wrong here is the sample code is showing the vertices are being drawn clockwise, not anti-clockwise:
v2-v3
\ /
v1
X_OBJSTART 1
X_OBJADDVERTEX 0, 0, 0, 0,0, RGB(255,255,255)
X_OBJADDVERTEX -20, 40, 0, 0,0, RGB(255, 0, 0)
X_OBJADDVERTEX 20, 40, 0, 0,0, RGB( 0, 0,255)
X_OBJEND
X_MAKE3D 1,20000,90
X_CULLMODE 1
X_CAMERA 0,1,50, 0,0,0
X_DRAWOBJ 1,0
SHOWSCREEN
MOUSEWAIT
This image #1 shows the order and vertices X and Y, it is the sample object (im not an artist but you can see the idea), this is clockwise.
In image #2: this is a screenshot of this code above.
So i think the problem is, the help file, stating "anti-clockwise".
I was making all my objects backwards because of that word lol :'(
One other thing, can you add a line in X_OBJ... stating a triangle alone in a group must be drawn starting "clockwise", to show the face.
[attachment deleted by admin]
oh dear. "clockwise" is a bad name.
Should be "cross product is posisitve".