View Full Version : Define plane from normal vector

 Rorschach02 February 2009, 10:38 PMI have a normal vector and a point, and I need to define a plane (three points) based on these. Can anyone help, I've read the maths and the geometric calculations thread but I'm not quite getting it.....
PiXeL_MoNKeY
02 February 2009, 11:34 PM
Have you looked at the "How do I align the UVW_Modifier's Gizmo to a selected face?" example in the Maxscript Help?

-Eric

SyncViewS
02 February 2009, 11:50 PM
Hi Rorschach,
if you need 3 generic points on the plane defined by position and normal vector, you can use the matrixFromNormal MaxScript function. The three point you'll get will be the first input position, and two points on plane defining an angle of 90 degrees distant 1 unit from the plane origin.

function planeFromNormal p3PlanePos p3PlaneNorm =
(
if ((classOf p3PlanePos) == Point3) and ((classOf p3PlaneNorm) == Point3) then
(
local m3Temp = matrixFromNormal (normalize(p3PlaneNorm))

-- points for visual test
point size:3 position:(p3PlanePos) wireColor:red
point size:3 position:(p3PlanePos + m3Temp.row1) wireColor:green
point size:3 position:(p3PlanePos + m3Temp.row2) wireColor:green
point size:3 position:(p3PlanePos + p3PlaneNorm) wireColor:blue

return #(p3PlanePos, (p3PlanePos + m3Temp.row1), (p3PlanePos + m3Temp.row2))
)
else
(
throw "Wrong input in function planeFromNormal()"
)
)
- Enrico

Rorschach
02 February 2009, 12:00 AM
Hi Rorschach,
if you need 3 generic points on the plane defined by position and normal vector, you can use the matrixFromNormal MaxScript function. The three point you'll get will be the first input position, and two points on plane defining an angle of 90 degrees distant 1 unit from the plane origin.

function planeFromNormal p3PlanePos p3PlaneNorm =
(
if ((classOf p3PlanePos) == Point3) and ((classOf p3PlaneNorm) == Point3) then
(
local m3Temp = matrixFromNormal (normalize(p3PlaneNorm))

-- points for visual test
point size:3 position:(p3PlanePos) wireColor:red
point size:3 position:(p3PlanePos + m3Temp.row1) wireColor:green
point size:3 position:(p3PlanePos + m3Temp.row2) wireColor:green
point size:3 position:(p3PlanePos + p3PlaneNorm) wireColor:blue

return #(p3PlanePos, (p3PlanePos + m3Temp.row1), (p3PlanePos + m3Temp.row2))
)
else
(
throw "Wrong input in function planeFromNormal()"
)
)
- Enrico

perfect... just what I was looking for, and I was sooo close ;)

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02 February 2009, 12:00 AM
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