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Contents 1 IPO Curves and IPO Keys(IPO曲线模式) 1.1 The IPO Curves(IPO曲线) 1.2 IPO Keys（IPO帧） 1.3 Other applications of IPO Curves(IPO曲线扩展) 1.4 The Time Ipo(时间IPO)

IPO Curves and IPO Keys(IPO曲线模式)

下面要讲的就是在BLENDER中最常用,功能也最强大的IPO曲线模式. IPO曲线模式:就是由IPO曲线来控制物体的属性变化.

The IPO Curves(IPO曲线)

IPO曲线是对物体的各种参数的保存及其控制下面我们将先从IPO窗口了解

想深入的了解IPO，就先来看看它的窗口吧。 blender默认的IPO面板就是非常好的，我们可以通过CTRL-LEFTARROW来调出来（同样你也可以通过窗口选项来调出）。如上图所示,我们可以在屏幕的右边看到. 你可以通过窗口选项让IPO窗口与任何一个窗口相联系,但是我们经常是将它和3D窗口同时排列运用的,你可以象对其它的窗口一样来移动或者缩放它.你可以通过插入菜单在其中加入IPO曲线.它将显示所有的IPO曲线及相应的用到的和可能用到的通道，这里特别说一下delta选项，比如dlocx，dlocy,dlocz等， 这些通道允许我们定义一个相对的偏移变化 ,这些通道可以用一条IPO曲线来控制不同的物体。补充一下，它可以在animation 'layers'中工作。你可以通过这种方法来达到微小的变化而不用再画复杂的曲线了。

Now we want to see exactly what happened. The first Screen initialised in the standard Blender start-up file is excellent for this. Activate it with CTRL-LEFTARROW. At the right we see the IPOWindow displayed (The IPO window.). You can of course turn any window into an IPO window with the pertinent Window Type menu entry, but it is more handy to have both a 3D window and an IPO window at the same time. This shows all the IPO Curves, the channels used and those available. You can zoom in and out the IPO Window and translate it just as every other Blender Window. In addition to the standard channels, which can be set via IKEY, you have the delta options, such as dLocX. These channels allow you to assign a relative change. This option is primarily used to control multiple objects with the same IPO. In addition, it is possible to work in animation 'layers'. You can achieve subtle effects this way without having to draw complicated curves.

IPO曲线的控制：

• 你可以通过单击每一个IPO通道的名称来实现隐藏/显示相应曲线,
• 你可以通过右键来单独选取一条曲线，也可以通过AKEY来选择全部IPO曲线,。
• 你也可以象在3D窗口中一样,运用Grabber（抓取） 和Size模式来处理IPO曲线。
• 我们也可以通过贝塞尔手柄来编辑IPO曲线

Each curve can be selected individually with the RMB. In addition, the Grabber and Size modes operate here just as in the 3DWindow. You can select IPOs also by clicking the color button in the right channel names column. By clicking the IPO channel name you effectively hide/show the relative curve. Selecting all curves (AKEY) and moving them to the right (GKEY), you can move the complete animation in time. Each curve can be placed in EditMode individually, or it can be done collectively.

贝塞尔手柄： 我们可以通过象编辑一条贝塞尔曲线一样通过贝塞尔手柄编辑IPO曲线，步骤为：

• 选择一条IPO曲线
• 按下TAB键

你就会看到在IPO曲线的节点处会有一个手柄一样的贝塞尔手柄，这个贝塞尔手柄的应用及其分类同贝塞尔曲线物体一样。 现在来介绍一下贝塞尔手柄分类：

• 自由手柄（黑色）： 这种手柄你可以按照你的愿望有运用它。 热键：HKEY（在自由手柄和排列手柄间转化）。
• 排列手柄（粉红色）： 这个这个将使手柄的三个点在一条直线上。 热键：HKEY（在自由手柄和排列手柄间转化）。
• 矢量手柄（绿色）： 手柄的各个部分都反指向上一个或者下一个手柄的方向。 热键：VKEY。
• 自动手柄（黄色）： 这个手柄将会由电脑自动分配一个长度和方向。 热键：SHIFT-HKEY。

你可以通过首先对一个手柄的中间一个点的选择来选择整个手柄，此时你可以通过拖动RMB来实现对手柄的移动。你也可以通过先选择手柄的两端的一个端点,再拖动RMB来实现手柄的旋转。 在旋转的过程将自动发生下面的变化：

• 自动手柄将变为排列手柄
• 矢量手柄将变化为自由手柄

在我们平常的曲线中默认的都是自动手柄,第一个和最后一个自动手柄经常都是水平的移动,这样可以创建一个不固定的变化。

Select the curves and press TAB. Now the individual vertices and handles of the curve are displayed. The Bézier handles are coded, like it is in the Curve Object:

• Free Handle (black). This can be used any way you wish. Hotkey: HKEY (switches between Free and Aligned).
• Aligned Handle (pink). This arranges all the handles in a straight line. Hotkey: HKEY (toggles between Free and Aligned).
• Vector Handle (green). Both parts of a handle always point to the previous or next handle. Hotkey: VKEY.
• Auto Handle (yellow). This handle has a completely automatic length and direction. Hotkey: SHIFT-HKEY.

Handles can be moved by first selecting the middle vertex with RMB. This selects the other two vertices as well. Then immediately start the Grab mode with RMB-hold and move. Handles can be rotated by first selecting the end of one of the vertices and then use the Grabber by means of the RMB-hold and move action. As soon as handles are rotated, the type is changed automatically:

• Auto Handle becomes Aligned.
• Vector Handle becomes Free.

"Auto" handles are placed in a curve by default. The first and last Auto handles always move horizontally, which creates a fluid interpolation.

IPO曲线和平常的曲线最大的区别在于： 它不能有环或者圆等在同一时间有两个或者以上的值的曲线， 因为每一个IPO曲线在一个时间点上只能有一个值与其相对应,因此它会自动的不出现环状或者圆等可以在同一时间内有两个或者更多值的曲线。但我们可以通过SHIFT-D键来复制一个曲线的一部分，并且将它们运用到另一个帧上面。

The IPOCurves have an important feature that distinguishes them from normal curves: it is impossible to place more than one curve segment horizontally. Loops and circles in an IPO are senseless and ambiguous. An IPO can only have 1 value at a time. This is automatically detected in the IPOWindow. By moving part of the IPOCurve horizontally, you see that the selected vertices move 'through' the curve. This allows you to duplicate parts of a curve (SHIFT-D) and to move them to another time frame.

It is also important to specify how an IPOCurve must be read outside of the curve itself. There are four options for this in theCurve>>Extend Mode Submenu in the IPO Window header(IPO extension options.).

IPO曲线的扩展模式： 下面我们将重点说一下IPO曲线的扩展模式及其相应的四个选项， 我们可能通过CURVE>>EXTEND MODE进入， 四个选项的效果见下图见下图：

The effect of each of these can be appreciated in (Extended IPOs.).

从左到右：

• 固定延伸模式：

在此模式下选取的IPO曲线的两端将以水平线向两边扩展，这是blender的默认选择。

• 外推延伸模式:

在此模式下选取的IPO曲线片断的两端，将以片断两端的延伸方向而延伸。

• 循环延伸模式:

在此模式下整个IPO曲线将会是所选取的片断的重复。

• 循环外推延伸模式:

在此模式下整个IPO曲线将会沿着所选片断的两端的延伸方向而不断的重复所选取的片断。

From left to right:

• Extend mode Constant: The ends of selected IPOCurves are continuously (horizontally) extrapolated. It is the default behaviour.
• Extend mode Extrapolation: The ends of the selected IPOCurves continue in the direction in which they ended.
• Extend mode Cyclic: The complete width of the IPOCurve is repeated cyclically.
• Extend Mode Cyclic Extrapolation: The complete width of the IPOCurve is extrapolated cyclic.

Interpolation Mode ： 对于贝塞尔曲线,还有一点要补充的是:当你在IPO窗口中按下TKEY时或者通Curve>>Interpolation Mode, 你会看到一个菜单和三个选项.三个选项的作用分别是：

• Constant （常量）：这种情况下整个IPO曲线将会在从一个节点A到下一个节点B的全部过程中的值都不会变，而只以节点A的值为准。而同样从B到下一点C时则以B的值为准。
• Linear（线性）：在这种情况下从节点A到节点B将会是一条连接AB的直线。
• Bezier（贝塞尔曲线）：在此情况下即我们平常所见的情况以曲线将两个节点相连 。

In addition to Béziers, there are two other possible types for IPOCurves. Use the TKEY command, and the dialog which then pops-up, or the Curve>>Interpolation Mode submenu entry to select them. The interpolation of the selected IPOCurves can be set to:

• Constant - after each vertex of the curve, this value remains constant. No interpolation takes place.
• Linear - linear interpolation occurs between the vertices.
• Bezier - the standard fluid interpolation.

一个IPO曲线不仅可以由插入菜单来创建也可以在IPO 窗口中手动通过CTRL-LMB命令来制定其规则为：

• 如果你没有创建IPO 块并已选择一个通道：

一个新的IPO 块和一条以你的鼠标所在位置的IPO曲线将自动建立。

• 如果你已经有一个IPO 块，并且你也选择了一个没有IPO曲线的通道则：

一条新的并且自动有一节点的IPO曲线将会自动生成 。

• 如果你已经有一个IPO块K并且也选择了一个已有IPO曲线的通道则：

一个新的节点将会添加到IPO曲线上去，但是当你选择多条IPO曲线或者在编辑模式下时则此方法将不会实现。

The IPO curves need not be set only by Key Framing. They can also be drawn 'by hand'. Use the CTRL-LMB command. Here are the rules:

• There is no IPO block yet (in this window) and one channel is selected: a new IPOBlock is created along with the first IPOCurve with one vertex placed where the mouse was clicked.
• There is already an IPO block, and a channel is selected without an IPOCurve: a new IPOCurve with one vertex is added.
• There is already an IPO block, and a channel is selected with an existing IPOCurve: A new point is added to the selected IPOCurve. This is not possible if multiple IPOCurves are selected or in EditMode.

例子： 如何实现一个物体的旋转：

Make an object rotate: This is the best method for specifying axis rotations quickly: Select the object; in the IPOWindow, press one of the "Rot" channels and use CTRL-LMB to insert two points. If the axis rotation must be continuous, you must use the Curve>>Extend Mode>>Extrapolation Menu entry. 使一个物件旋转: 这是快速指定轴向转动的最好方法: 选择物件; 在 IPO窗口中, 按 " Rot" 通道和 使用 CTRL-LMB 插入二个点。如果轴向必须是连续的旋转,那你一定要使用Curve>>Extend Mode>>Extrapolation 菜单条目.

One disadvantage of working with motion curves is that the freedom of transformations is limited. You can work quite intuitively with motion curves, but only if this can be processed on an XYZ basis. For a location, this is outstanding, but for a size and rotation there are better mathematical descriptions available: matrices (3x3 numbers) for size and quaternions (4 numbers) for rotation. These could also have been processed in the channels, but this can quite easily lead to confusing and mathematically complicated situations. Limiting the size to the three numbers XYZ is obvious, but this limits it to a rectangular distortion. A diagonal scaling such as 'shearing' is impossible. Simply working in hierarchies can solve this. A non-uniform scaled Parent will influence the rotation of a Child as a 'shear'. The limitation of the three number XYZ rotations is less intuitive. This so-called Euler rotation is not uniform - the same rotation can be expressed with different numbers - and has the bothersome effect that it is not possible to rotate from any position to another, the infamous gimbal lock. While working with different rotation keys, the user may suddenly be confronted with quite unexpected interpolations, or it may turn out to be impossible to force a particular axis rotation when making manual changes. Here, also, a better solution is to work with a hierarchy. A Parent will always assign the specified axis rotation to the Child. (It is handy to know that the X, Y and Z rotations are calculated one after the other. The curve that affects the RotX channel, always determines the X axis rotation). Luckily, Blender calculates everything internally with matrices and quaternions. Hierarchies thus work normally, and the Rotate mode does what you would expect it to. Only the IPOs are a limitation here, but in this case the ease of use prevails above a not very intuitive mathematical purity.

运用IPO曲线的一个不好的方面是它将限制自由的变形，你可以很直观的通过曲线来工作，但是它必须是运行在一个XYZ基础上的，对于位置，它是比较突出的，但是对于缩放和旋转，它有更好的数学解释：矩阵相应于缩放，quaternions相应于旋转。它们同样也可以在通道中运行，但是它很容易导致复杂的情况，将缩放局限于XYZ将会导致成一个矩形失真。一些缩放比如'shearing'将不可能运用，但是一个简单的层次工作将会解决这个问题：一个不一致的父亲缩放将会使孩子的旋转类似于'shear'。对于旋转，XYZ的限制不是很直观的，这个称为欧拉旋转的将会不怎么一致，同样的旋转将会用不同的数字来表示，并且可能会引起不会旋转的麻烦，这就是声名狼藉的万向平衡限制。当同时有不同的旋转帧，你可能发现旋转被修改，或者当你进行人为修改时它将不可能进行旋转。这时同样的，你可以通过层次来解决这个问题，一个父亲用来指定孩子的特定旋转。

IPO Keys（IPO帧）

对于IPO曲线模式，和它最容易搭配工作的就是IPO帧了。我们接着以前的例子讲，我们已经在第1帧和第31帧分别用插入菜单建立了IPO曲线，在屏幕的右边，你可以看到IPO窗口（CTRL+LEFTARROW），现在我们将帧调到第21帧。

此处为一些解释： Join (结合) : 大概的意思是,如果一条IPO运动曲线上有太多重复的关键帧,一个一个用手删除,工作量非常大;框选一堆一起删除又会改变IPO运动曲线的形态,这时 JKEY (Join) 命令可以在保持曲线的形态的前提下删除对动画影响不明显的关键帧,提高工作效率.

All Selected : 只要框选了的顶点不管距离多远,在保持曲线的形态的前提下删除多余关键帧.

Selected Doubles : 在保持曲线的形态的前提下,只合并选择的重叠顶点.

The easiest way to work with motion curves is to convert them to IPO Keys. We return to the situation in the previous example: we have specified two positions in an object IPO in frame 1 and frame 31 with IKEY. At the right of the screen, you can see an IPO Window. We set the current frame to 21 (The IPOKey mode.).

Press KKEY while the mouse cursor is in the 3DWindow. Two things will happen now:

• The IPOWindow switches to IPOKey mode.
• The selected object is assigned the "DrawKey" option.

当你激活了3D窗口以后按下K键，现在将发生两件事情：

• IPO窗口转变为IPO帧模式。
• 选择的物体将被指定为"DrawKey"选项

The two actions each have separate meanings.

• The IPOWindow now draws vertical lines through all the vertices of all the visible IPOCurves (IPOS are now black). Vertices with the same 'frame' value are linked to the vertical lines. The vertical lines (the "IPOKeys") can be selected, moved or duplicated, just like the vertices in EditMode. You can translate the IPOKeys only horizontally.
• The object is not only shown in its current position but 'ghost' objects are also shown at all the Key positions. In addition to now being able to visualize the key positions of the object, you can also modify them in the 3DWindow. In this example, use the Grab mode on the object to change the selected IPOKeys.

这两个行为有各自不同的含义：

• IPO窗口现在将出现一些穿过可见IPO曲线节点的垂直线，节点的值将同垂直线相互联系。垂直线（即IPO帧）可以选择，移动或者复制，就象节点在编辑模式中一样，但是你只可以水平移动它。
• 在3D窗口中物体不仅显示现在的位置也在关键帧显示阴影物体的位置，你可以看到物体在运动中所经过的关键点的位置，同时你也可以在3D窗口修改它们，在这个例子中，你可以通过GRAB模式来改变所选择的IPO帧。

Below are a number of instructions for utilizing the power of the system:

• You can only use the RMB to select IPOKeys in the IPOWindow. Border select, and extend select, are also enabled here. Select all IPOKeys to transform the complete animation system in the 3DWindow.
• The "Insert Key" always affects all selected objects. The IPOKeys for multiple objects can also be transformed simultaneously in the 3DWindow. Use the SHIFT-K command: Show and select all keys to transform complete animations of a group of objects all at once.
• Use the PAGEUP and PAGEDOWN commands to select subsequent keys in the 3DWindow.
• You can create IPOKeys with each arrangement of channels. By consciously excluding certain channels, you can force a situation in which changes to key positions in the 3DWindow can only be made to the values specified by the visible channels. For example, with only the channel LocX selected, the keys can only be moved in the X direction.
• Each IPOKey consists of the vertices that have exactly the same frame value. If vertices are moved manually, this can result in large numbers of keys, each having only one curve. In this case, use the JKEY ("Join") command to combine selected IPOKeys. It is also possible to assign selected IPOKeys vertices for all the visible curves: use IKEY in the IPOWindow and choose "Selected keys".
• The DrawKey option and the IPOKey mode can be switched on and off independently. Use the button EditButtons->DrawKey to switch off this option or object. You can switch IPOKey mode on and off yourself with KKEY in the IPOWindow. Only KKEY in the 3DWindow turns on/off both the DrawKey and IPOKey mode.

下面将是一些对其功能的说明：

• 在IPO窗口中你可以通过右键来选择IPO帧，范围选择，扩展选择也是可以的，你可以在3D窗口中选择全部的IPO帧并整体移动来实现动画系统的移动。
• 插入菜单将会影响所有选择的物体，关系多样物体的IPO帧也可以同时在3D窗口中移动，通过SHIFT-K命令：Show and select all keys可以同时移动整组的物体。
• 在3D窗口中可以通过PAGEUP，PAGEDOWN来依次选择关键节点帧。
• 你可以为每一个指定的通道创建IPO帧，但是对于一些特定的通道，你可能会面对一些问题，比如，当你只选择了LocX通道，则帧只能在X方向移动。
• 不同的IPO帧可能含有一些相同帧值的节点，但是当一些节点被人为移动后，就会产生新的节点，并产生新的曲线，这种情况下可以通过J键来结合选择的IPO帧，同样也可以将选择的IPO帧的节点指定给所有可见的曲线：在IPO窗口按下I键并选择"Selected keys"
• 你可以通过在3D窗口中按下K键来打开/关闭IPO帧模式。

Other applications of IPO Curves(IPO曲线扩展)

IPO除了能用于控制一个物体的运动外它，还有其它的应用,在IPO窗口的菜单中我们可以选择IPO BLOCK的类型.到目前为止我们所说的类型都是Object IPO,但是它也有Material（材料） IPO, World IPO, Vertex（顶点） Keys IPO, Constraints（约束） IPO and Sequence（序列） IPO. 但不是每一个选项都会出现的,它会根据我们的操作而自动出现.比如:曲线IPO就只出现在我们所选择的物体是一条曲线而不是一个曲面时;灯光IPO就只出现在我们所选择的是灯光时.

There are several other application for IPOs other than just animating an Object movement. The IPO Type Menu Buttons in the header (The IPO window.) allow IPO Block type selection, the active one there is the Object IPO described up to now, but there are Material IPO, World IPO, Vertex Keys IPO, Constraints IPO and Sequence IPO. Not every entry is always present, depending on context. Curve IPO block appears if the selected object is a curve and not a Mesh, the Lamp IPO only appears if the selected object is a lamp.

材料IPO是一个可以动态的控制材料,就象对于平常的物体一样IPO曲线可以指定材料的'key positions(关键位置)'.当鼠标在ButtonsWindow（按钮窗口）中,我们按下IKEY,此进会有一带有关于不同的材料的变量的选项的弹出菜单出现，如果你是在Material, Lamp or World IPO Block中这时一个小的数字按钮将会在IPO窗口的工具栏靠近IPO类型菜单的地方出现.它显示了那一个纹理通道正在被激活，8个通道的映射都可以被IPO曲线控制！严格的说对于纹理两个不同的运动是可以的，因为物体可以给予其它物体相配的纹理（在BLENDER中每一个物体都都可以做为纹理的原料，为了做到这点,绿色的"Coordinates input" 按钮中的"Object"选项一定要选上,并且这个物体的名称也一定要写上，此时在渲染时就会发生一个逆变换。) 它可以通过物体的位置，大小，角度的不同而改变的物体的纹理。说远点，在BLENDER中的每一帧中,它都可以根据不同的情况而下载不同的图象做为纹理.

Material IPO is a way of animating a Material. Just as with objects, IPO Curves can be used to specify 'key positions' for Materials. With the mouse in the ButtonsWindow, the command IKEY calls up a pop-up menu with options for the various Material variables. If you are in a Material, Lamp or World IPO Block then a small Num Button appears next to the IPO type Menu in the IPO Window toolbar. This indicates which texture channel is active. The mapping for all 8 channels can be controlled with IPOCurves! Strictly speaking, with textures two other animations are possible. Since Objects can give texture coordinates on other objects (Each object in Blender can be used as a source for texture coordinates. To do this, the option "Object" must be selected in the green "Coordinates input" buttons and the name of the object must be filled in. An inverse transformation is now performed on the global render coordinate to obtain the local object coordinate) it is possible to animate the texture simply by animating the location, size, and rotation of the object. Furthermore, at each frame, Blender can be made to load another (numbered) Image as a texture map instead of having a fixed one. It is also possible to use SGI movie files or AVI files for this.

The Time Ipo(时间IPO)

通过时间IPO曲线（TimeIpo curve）我们可以很熟练的操作物体运动的时间,而不需要再改变物体的运动或者其它IPOS.实际上它改变了animation time在global animation time (Linear（线性） time IPO)上的映射.

With the TimeIpo curve you can manipulate the animation time of objects without changing the animation or the other Ipos. In fact, it changes the mapping of animation time to global animation time (Linear time IPO).

Linear time IPO（线性时间IPO）

为了理解这个,我们可以做一个简单的关键帧动画例子,就做一个50帧的好了,从一个位置移到另一个位置,现在选择IPO时间选项,并且建立一个从(1,1)到（50，50）的时间IPO（TimeIpo）.我们可以通过NKEY然后输入一个数字,很容易的控制一个IPO的起点和终点.在两帧之间,如果你的TIMEIPO的斜率是正值,则物体就会前进,前进的速度是由斜率来控制的,斜率大于1则运动的速度大于正常的速度,若小于1则小于,若为1则表于速度无变化,如果斜率为负值则表示物体在动画中将倒退.TimeIpo在控制粒子系统时最为有趣,它允许你“冻结”粒子,或者让粒子以物体的形式运动而不是放射.其它可能发生的事情就是:可能会使时间失效,或者减慢物体的运动.

多条TimeIpo 你需要复制TimeIpo给所有的运动系统使整个运动变慢,但也可以只使有的运动停止,有的继续运动,比如:如果运用到摄影机上,就可以得到很多有趣的效果.

To grasp this concept, make a simple keyframe-animation of a moving object, from a position to another in, say, 50 frames. Then select the Time channel and create a TimeIpo in the IpoWindow going from point (1,1) to point (50,50). It is easy to set the start and end point of an IPO by using NKEY and entering the values numerically. In frames where the slope of the TimeIpo is positive, your object will advance in its animation. The speed depends on the value of the slope. A slope bigger than 1 will animate faster than the base animation. A slope smaller than 1 will animate slower. A slope of 1 means no change in the animation, negative power slopes allow you to reverse the animation. The TimeIpo is especially interesting for particle systems, allowing you to "freeze" the particles or to animate particles absorbed by an object instead of emitted. Other possibilities are to make a time lapse or slow motion animation. {{Note|Multiple Time IPOs| You need to copy the TimeIpo for every animation system to get a full slow motion. But by stopping only some animations, and continue to animate, for example, the camera you can achieve some very nice effects (like those used to stunning effect in the movie "The Matrix")}

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