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      <title>Blend Factor</title>
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      <div class="title_topic7" id="xps10_pagetitle">Blend Factor</div>
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      <p class="para_topic"> The value in the Blend Factor field determines the smoothness of the trajectory path through key frames not using the Turntable Motion option. A blend factor of zero for a key frame means that the camera moves directly along the trajectory to the key frame position, and then makes a sharp turn to the next key frame. Values greater than zero for the Blend Factor produce rounded corners and a smoother trajectory path. (You could describe this value as determining the amount of inertia used while moving the camera.</p>
      <p class="para_topic"> When you enter a value in the Blend Factor field, use the Update Frame button to make the changes effective for the frame.</p>
      <p class="para_topic"> A rough example of blending a trajectory path is shown in below. The spline path is a cubic hermite curve where the tangency vector at each vertex is the bisector of the angle.</p>
      <p align="center"><img align="bottom" src="graphics/vie_8viewfr80.gif"></p>
      <p class="para_topic"> Example of Camera Path Splines and Blending Factors</p>
      <p class="para_topic"> The figure above shows 3 key frame points connected by lines, and also by a splined path. The larger the blend factor on the key frame, the larger the deviation from the linear path between frames. Regardless of the value of the blend, the trajectory will always go through the key frame point. The spline curve passing through the key frame point will be tangent and continuous unless the Blend factor is zero or negative.</p>
      <p class="para_topic"> The actual path of the trajectory is dependent on the distance between key frames, the number of steps between key frames and the blend factor. For a given distance between key frames and a constant value for the blend, the more steps you take, the tighter the spline will follow a linear path. To increase the number of steps, but maintain the same curved spline path, you will need to also increase the Spline blending factor.</p>
      <p class="para_topic"> There are two reasons you might set the Spline blending factor to zero. One reason would be to have the camera move along a line with no deviations. The second reason would be if you want the camera to hold a location for some number of frames. To get that effect, set two key frames to the same location, establish the number of frames to hold (delay) in the second key frame, then set the blend factor to zero. If the blend factor is not zero, the camera will make a small loop instead of holding still.</p>
      <p class="para_topic"> You can also set the Spline blending factor to a negative value. This causes the trajectory to follow an unnatural path, reversing the spline direction in the example above, but may present an interesting visual effect.</p>
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