# the angle from point A to point B (where the mouse is) - Macromedia Director 3D

i'm trying to figure out the angle between a point in my sceane and the point at which the mouse has been clicked. i've been looking at 3dD world ([url]http://www.dmu.com/[/url]) but my maths skills arent strong enough to figure it out from the starting point that gives me. so i have something like: mousePlace = the mouseLoc - point(sprite(1).left, sprite(1).top) tRollOverModel = sprite(1).camera.modelUnderLoc(mousePlace) if tRollOverModel <> 0 and _mouse.mouseDown then targ = sprite(1).camera.spriteSpaceToWorldSpace(mousePlac e) put "mouseover " & targ end if this tells me if ive clicked on the model and gives me "a" reading on where the mouse is. ...

1. ## the angle from point A to point B (where the mouse is)

i'm trying to figure out the angle between a point in my sceane and the
point at which the mouse has been clicked. i've been looking at 3dD
world ([url]http://www.dmu.com/[/url]) but my maths skills arent strong enough to
figure it out from the starting point that gives me.

so i have something like:

mousePlace = the mouseLoc - point(sprite(1).left, sprite(1).top)

tRollOverModel = sprite(1).camera.modelUnderLoc(mousePlace)

if tRollOverModel <> 0 and _mouse.mouseDown then
targ = sprite(1).camera.spriteSpaceToWorldSpace(mousePlac e)
put "mouseover " & targ
end if

this tells me if ive clicked on the model and gives me "a" reading on
where the mouse is. i want to rotate a model to point at where the mouse
is.

any help would be much apreciated.

jon
Jon Moyles Guest 2. ## Re: the angle from point A to point B (where the mouseis)

Check out pointat()
and if you need, anglebetween()
walfridson Guest 3. ## Re: the angle from point A to point B (where the mouseis)

so, time for a little math :)

A, B -> points
v = B-A ->vector from A to B
vx -> x axis
alpha -> angle between v and vx

v . vx
--------- = cos alpha
|v| . |vx|
juroo Guest 4. ## Re: the angle from point A to point B (where the mouse is)

thanks guys

i havent solved it yet though. i apologise for my ignorance.

heres whats going on. i have a pendulum hanging in my sceane, i want to
point the pendulum towards a mouse click (and then have it swing, the
swinging part works fine). pointing it at a mouse click is proving a lot
harder.

i want the pendulum to only move on one plane (it rotates on its x axis).

heres what i'm trying to do. i find the place where the user has clicked
(targ) i find the location of the fulcrum (fulcrumLoc) and i find the
location of the camera (cameraLoc). then i try to get the angle from the
fulcrumLoc to the point on the sightLine (targ - cameraLoc) on the yz
plane (where to turn the pendumlum to point at the mouse).

mousePlace = the mouseLoc - point(sprite(1).left, sprite(1).top)
cameraLoc = sprite(1).camera.worldPosition
fulcrumLoc = member("pendulum04").model("fulcrum01").worldPosit ion
targ = sprite(1).camera.spriteSpaceToWorldSpace(mousePlac e)
sightLine = targ - cameraLoc
pendulumAngle =
member("pendulum04").model("fulcrum01").transform. position.angleBetween(sightLine)

as you can see i dont know what i'm doing. for one thing i dont know how
to work on a point in the yz plane. for another
So i still need help. I apreciate the efforts already made and would
really like it if somebody can explain what i'm doing wrong.

thanks
jon
Jon Moyles Guest #### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•