I have a script (shown below)
the first line assigns a specific object name to an attribute.
This will always be self-referencing.
How do I make this automatic so that it’s easy to drop the script on multiple objects?
Currenty:
obj = $Ball
want something like:
obj = thisObj.name
Can’t seem to find the correct syntax. Apologies for the newbie question.
Full script:
obj = $Ball
timeres = 1f
fn getrot t =
(
if t<=0f then return quat 0 0 0 1 – t=0 => no rotation
t0 = t-timeres – previous frame time
t1 = t – current time
rot0 = getrot(t0) – previous rotation:
p0 = at time t0 obj.position– previous position
p1 = at time t1 obj.position– current position
if(p0==p1) then return rot0 – no distance is traveled
dif = p1-p0 – difference in positions
len = Length(dif) – distance that’s traveled
vec = dif / len – normalized movement vector.
r0 = at time t0 obj.radius – previous radius
r1 = at time t1 obj.radius – current radius
rotax = cross vec [0, 0, 1] – rotation axis
angle = 360*len/((r0+r1)*pi)– rotation amount (in degs)
rotdif = quat angle rotax – rotation from t0 to t1
rot1 = rot0 + rotdif – total rotation
)
getrot(currentTime)
If you want to use your script for multiple objects:
(
timeres = 1f
fn getrot t =
(
selObjsArr = selection as array
for obj in selObjsArr do
(
if t<=0f then return quat 0 0 0 1 – t=0 -- no rotation
t0 = t-timeres --previous frame time
t1 = t – current time
rot0 = getrot(t0) -- previous rotation:
p0 = at time t0 obj.position-- previous position
p1 = at time t1 obj.position-- current position
if(p0==p1) then return rot0 -- no distance is traveled
dif = p1-p0 -- difference in positions
len = Length(dif) -- distance that’s traveled
vec = dif / len -- normalized movement vector.
r0 = at time t0 obj.radius -- previous radius
r1 = at time t1 obj.radius --current radius
rotax = cross vec [0, 0, 1] -- rotation axis
angle = 360*len/((r0+r1)*pi)-- rotation amount (in degs)
rotdif = quat angle rotax --rotation from t0 to t1
rot1 = rot0 + rotdif -- total rotation
)
)
getrot(currentTime)
)Hi,
Thanks for the reply. Seems to be an error though.
call needs function or class, got: 73f
I did neglect to mention previously that this script is used as a rotation script controller for the object in question (in example above “Ball”).
Any ideas?
Thanks in advance.
whole function is wrong …
fn getrot t =
(
if t<=0f then return quat 0 0 0 1 – t=0 => no rotation
t0 = t-timeres – previous frame time
t1 = t – current time
rot0 = getrot(t0) – previous rotation: ...the function recursively goes to zero time … which doesn’t make sense
here is how the function template might look:
fn getRot obj t offset:1f =
(
rot = quat 1
if t > 0f do
(
...
rot = ...
)
rot
)no… this is wrong.
the best solution is to pass object to the getrot function
This is wrong in this particular case, or in general?
the function must return some kind of “rotation” value. in your implementation the function used for the node’s array … so at least it should return an array … which doesn’t make sense for recursive using
I doubt at all that this function, as shown, can do anything reasonable
My goal was to show him how to apply the code he have to multiple objects. I didn’t read the rest of the code.
Thanks for the replies. There was an error in the code I pasted. The corrected version is below. It definitely works and is functioning as I require. But I have to change the object name each time I apply it to a new object. I want to mod the code so it knows which object it is in.
I apply the script to the rotation controller script. If you animate a sphere objects motion, this applies proper roll rotations without nasty gimbal lock.
With this corrected code… anyone have suggestions?
Thanks for all the inputs so far.
obj = $Ball
timeres = 1f
fn getrot t =
(
if t<=0f then return quat 0 0 0 1 – t=0 => no rotation
t0 = t-timeres – previous frame time
t1 = t – current time
rot0 = getrot(t0) – previous rotation:
p0 = at time t0 obj.position– previous position
p1 = at time t1 obj.position– current position
if(p0==p1) then return rot0 – no distance is traveled
dif = p1-p0 – difference in positions
len = Length(dif) – distance that’s traveled
vec = dif / len – normalized movement vector.
r0 = at time t0 obj.radius – previous radius
r1 = at time t1 obj.radius – current radius
rotax = cross vec [0, 0, 1] – rotation axis
angle = 360*len/((r0+r1)*pi)– rotation amount (in degs)
rotdif = quat angle rotax – rotation from t0 to t1
rot1 = rot0 + rotdif – total rotation
)
getrot(currentTime)
Hmmm… some reason when I post the script here in the message body it changes something (perhaps minus’ into dashes, dunno) when I paste it back it buggers up.
post it inbetween [code] ... [/code] tags