NiTriShape Apply Transform

const
  PI = 3.14159265359;

procedure ApplyTransform(aTriShape: TwbNifBlock);
var
  scale: single;                       // Transform scale.
  translation: array[1..3] of single;  // Transform translation.
  rotation: array[1..9] of single;     // Transform rotation matrix.
  y, p, r: single;                     // Yaw / Pitch / Roll for rotation matrix.

  sinX, cosX, sinY, cosY, sinZ, cosZ: single; // temp trigonometry variables.
  pX, pY, pZ: single; // point coordinates.
  tX, tY, tZ: single; // transformed point coordinates.

  TriShapeData: TwbNifBlock; // Shape Data to transform point.

  // stuff to iterate over things.
  ref: TdfElement;
  i, n: integer;
  arr: TdfElement;

  sl: TStringList;
begin

  scale := aTriShape.NativeValues['Transform\Scale'];

  translation[1] := aTriShape.NativeValues['Transform\Translation\X'];
  translation[2] := aTriShape.NativeValues['Transform\Translation\Y'];
  translation[3] := aTriShape.NativeValues['Transform\Translation\Z'];

  sl := TStringList.Create;
  sl.Delimiter := ' ';
  sl.StrictDelimiter := false;
  sl.DelimitedText := aTriShape.EditValues['Transform\Rotation'];
  y := StrToFloat(sl[0]) * PI / 180;
  p := StrToFloat(sl[1]) * PI / 180;
  r := StrToFloat(sl[2]) * PI / 180;
  sl.Free;

  sinX := sin(y);
  cosX := cos(y);
  sinY := sin(p);
  cosY := cos(p);
  sinZ := sin(r);
  cosZ := cos(r);

  rotation[1] := cosY * cosZ;
  rotation[2] := -cosY * sinZ;
  rotation[3] := sinY;
  rotation[4] := sinX * sinY * cosZ + sinZ * cosX;
  rotation[5] := cosX * cosZ - sinX * sinY * sinZ;
  rotation[6] := -sinX * cosY;
  rotation[7] := sinX * sinZ - cosX * sinY * cosZ;
  rotation[8] := cosX * sinY * sinZ + sinX * cosZ;
  rotation[9] := cosX * cosY;

  for i := 0 to Pred(aTriShape.RefsCount) do begin
   ref := aTriShape.Refs[i];
   TriShapeData := TwbNifBlock(ref.LinksTo);
   if Assigned(TriShapeData) then begin
     if SameText(TriShapeData.BlockType, 'NiTriShapeData') then begin
       n := TriShapeData.NativeValues['Num Vertices'];
       arr := TriShapeData.Elements['Vertices'];
       for i := 0 to Pred(n) do begin
         pX := arr[i].NativeValues['X'];
         pY := arr[i].NativeValues['Y'];
         pZ := arr[i].NativeValues['Z'];

         tX := (pX * rotation[1] + pY * rotation[2] + pZ * rotation[3]) * scale + translation[1];
         tY := (pX * rotation[4] + pY * rotation[5] + pZ * rotation[6]) * scale + translation[2];
         tZ := (pX * rotation[7] + pY * rotation[8] + pZ * rotation[9]) * scale + translation[3];

         arr[i].EditValue := FloatToStr(tX) + ' ' + FloatToStr(tY) + ' '+ FloatToStr(tZ);
       end;
    end;
   end;
  end;

  aTriShape.EditValues['Transform\Translation'] := '0.000000 0.000000 0.000000';
  aTriShape.EditValues['Transform\Rotation']    := '0.000000 0.000000 0.000000';
  aTriShape.EditValues['Transform\Scale']       := '1.000000';
end;