Model 3 3D Hardware
Main Tree Node (a.k.a Scene Descriptor) description

Index |	Description

  0	Unknown
  1	Sub tree node link
  2	Next main tree link
  3	Unknown
  4	Sun Light Vector Z component
  5	Sun Light Vector Y component
  6	Sun Light Vector X component
  7	Sun Light Intensity (floating point)
  8	Unknown
  9	Unknown
  10	Sun Light Ambient ???
  11	Unknown
  12	Unknown
  13	Unknown
  14	Unknown
  15	Unknown
  16	Unknown
  17	Unknown
  18	Unknown
  19	Unknown
  20	High word: Viewport Y width (14.2 fixed point ?)
	Low word:  Viewport X width
  21	Unknown
  22	Matrix base address
  23	Unknown
  24	Unknown
  25	Unknown
  26	High word: Viewport Y start (12.4 fixed point ?)
	Low word:  Viewport Y start
  27	Unknown
  28	Unknown
  29	High word: Light Y size
	Low word:  Light Ypos (13.3 fixed point ?)
  30	High word: Light X size
	Low word:  Light Xpos
  31	Light extent (floating point)
  32	Unknown, Light Start ? (floating point)
  33	Unknown
  34	Fog Color
  35	Fog Density (floating point)
  36	Unknown, looks like a 16.16 fixed point value. Could be Fog Ambient
  37	Fog Offset
  38	Unknown
  39	Unknown
  40	Unknown
  41	Unknown
  42	Unknown
  43	Unknown
  44	Unknown
  45	Unknown
  46	Unknown
  47	Unknown