MAXScript101 3.2_Working With Controllers

MAXScript101 3.2_Working With Controllers
-- Add & Delete key frames, manipulate key parameter

 

 

1. controller

【译】The track property is a simple synonym for controller. If an animatable property does not yet have a controller assigned, the isAnimated property returns false and the controller, track, and keys properties return undefined.

 

轨道(track)属性是控制器(controller)的别名。如果一个可动画属性还没有赋予控制器的话，<property>.isAnimated 返回false, controller, track, keys 返回undefined。

 

-- Controller Operation (1): assign a controller to a variable, any animatable property has controller
c = $Box01.height.controller -- return: undefined

 

-- Controller Operation (2): construct a path_constraint controller
pc = path_constraint follow: true bank: true path: $line01
$Box01.pos.controller = pc

 

-- Controller Operation (3): access and adjust controllers paramters
$Box01.pos.controller.bankAmount -=0.25

 

-- Controller Operation (4): copy controller instance using =, or copy
$Box01.scale.controller = $Box02.scale.controller

if $Box01.height.controller == undefined then
(
$Box01.height.controller = noise_float frequency: 0.74 fractal: false
$Sphere01.radius.controller = copy $Box01.height.controller
)

 

2. get keys
MAXScript有三类关键帧：
Bezier
TCB
Barycentric Morph

 

key有三个属性值：
.time -- which holds the time of the key
.value -- which holds the keys value, and
.selected -- which is true or false if the key is selected or not

 

eg.
animate on for i in 0 to 100 by 20 do
at time i
(
scale $Sphere01 [1.1, 1.1, 1.1]
)

keys = $Sphere01.scale.controller.keys -- #keys(0f, 20f, 40f, 60f, 80f, 100f)
keys[1] -- #Bezier Scale key(1 @ 0f)
-- can print or assign the property of keys
keys[1].time -- 0f
keys[1].value -- [1.77156,1.77156,1.77156]
keys[1].selected -- false
for k in keys do format "% at %/n" k.value k.time
--[1.77156,1.77156,1.77156] at 0f
--[1.94872,1.94872,1.94872] at 20f
--[2.14359,2.14359,2.14359] at 40f
--[2.35795,2.35795,2.35795] at 60f
--[2.59374,2.59374,2.59374] at 80f
--[2.85312,2.85312,2.85312] at 100f

3. 实例
1）物体的上方（即它的z轴方向）有一个圆形轨道；圆心为物体中心上方（与相机等高），半径为摆好初始位置时，相机的位置到圆心的距离；
2）在相机进行step 时，target位置始终在物体中心位置，相机step的位置为圆形轨道的lengthInterp点
3）该函数的使用比较一般性，当stepsNum个数较大时，变成了相机的旋转
4）lengthInterp点的个数等于关键帧的个数，在这里是stepsNum

-- Camera step around obj, stepsNum means the keys's number -- Step Camera according to the position data from shape interpolation method -- here we can use helper to replace obj parameter -- before using this funtion, you should set an appropriate camera function stepCam cam obj stepsNum = ( -- step1: ensure clean pos controllers if classOf cam.pos.controller != bezier_position then cam.pos.controller = bezier_position() else deleteKeys Cam.pos.controller if classOf cam.target.pos.controller != bezier_position then cam.target.pos.controller = bezier_position() else deleteKeys cam.target.pos.controller if classOf obj.pos.controller != bezier_position then obj.pos.controller = bezier_position() else deleteKeys obj.pos.controller -- step2: create camera circle path according to the position of camera and obj tracPos = obj.pos + [0, 0, cam.pos.z-obj.pos.z] tracRad = distance cam.pos tracPos camTrac = circle radius:tracRad pos:tracPos -- step3: compute the step locations along the circle path -- stepsNum equals to the number of the path knots delta = 1 / (stepsNum - 1) as float stepLocations_Cam = #() for u in 0 to 1 by delta do ( local knot_obj = lengthInterp camTrac u append stepLocations_Cam knot_obj ) -- step4: grab controllers for ease of access local cc = cam.pos.controller, tc = cam.target.pos.controller, -- step5: -- init frame counter and local curFrame = 0, frames = (animationRange.end - animationRange.start)/(stepsNum - 1) as float -- add keys for camera and its target for i=1 to stepsNum do ( -- add & grab new keys for current time local ck = addNewKey cc curFrame, tk = addNewKey tc curFrame -- set new key value & tangent type ck.value = stepLocations_Cam[i]; ck.inTangentType = #step tk.value = obj.pos; tk.inTangentType = #step -- bump frame time over desired time-at-pos curFrame += frames ) ) -- useage stepCam $Camera01 $Box01 20 

 

4. 有关time, key, controller 操作，详细查询MAXScript Reference 相关主题：
. Controller Key Functions: eg. addNewKey ...
. Controller Time Functions: eg. getTimeRange ...
. Controller Common Properties, Operators and Methods: eg. <controller>.keys ...
. Controller Out-Of-Range Functions: eg. getBeforeORT...