*Flavor 8 - Polygon Properties (planes)*

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** LONG PURPOSE**
** ---- -------**
** 00-03 Flavor Flag (08 00 00
80)**
** 04-07 Value #A**
** 08-11 Value #B**
** 12-15 Value #C**
** 16-23 Value #D (read 8 byte words
instead of 4)**
** 24-27 Flavor Offset #1**
** 28-31 Flavor Offset #2**
** 32-35 Flavor Offset #3**

**Ax + By + Cz + D = 0**

**Flavor Offset #1 #2 #3**
** I have found calls to
Flavor #1, #4, #7, #8, #11, #12 and #15 offsets.**

**In Andre's words :**

**First 3 values set the x,y and z values of a vector set at a 90 degree
angle from the plane the polygon is drawn on.**
**The angle is 90 degrees for any line that can be drawn within that
plane. Marcelo named it the directional vector (DV).**

**The vector is always drawn towards the viewer. So if you want a polygon
to be drawn in both the driving direction and when riding the track backwards
you have to have 2 polygons with 2 DV's that have a 180 degree angle between
eachother.**

**To extrapolate the values from 2 points:**

**The Dot Product**
**(x1, y1, z1) . (x2, y2, z2) = (x1)(x2) +
(y1)(y2) + (z1)(z2)**

**the dot product is in the equation to find the plane.**
**I can't remember exact meaning of dot product (cross is normal vector),**
**but dot is a projection or something (words of Jon).**

**It's needed for the plane equation**

**----------**
**({x, y, z}-point).normal**
** **
**point is the point which is used for the start of the 2**
**vectors which are made from other 2 points to the point.**
**Then cross product of those vectors for normal.**

**(words of Jon again)**

**I have found this webpage to be a big help on understanding this.**
**http://reality.sgi.com/cgi-bin/bspfaq/bsp?8.txt**