5.85. Vertex Fdp (element)

5.85.1. Attributes

5.85.2. Description

This element defines a fdp vertex in a subdivision (a mesh). Fdp vertices are used to define the weights of the keypoints in order to control the vertex displacements.

The index attribute defines the index of the controlled vertex v_c. The k value of the size attribute defines the number of keypoints that control the vertex v_c.

This element must contain k 4-uples made of a keypoint index k_i and 3 keypoint weights wx_i, wy_i, and wz_i. The displacement of v_c is computed from the k translations tx_i, ty_i, and tz_i associated with each keypoints k_i as follows:

Equation 5-4. Linear Interpolation

5.85.3. Expected child

None.

5.85.4. Expected values

k 4-uples made of 1 integer value (the keypoint index) and 3 float values (the wx, wy, wz weights of the tx, ty, tz translation coordinates).

5.85.5. Example

The example below defines the 30th fdp vertex that is controlled by the 5th, 7th, and 27th keypoints. Its x-translation is 0.318388 × tx₅, its y-translation is 0.55718 × ty₅ - 0.00536683 × ty₇ - 0.179829 × ty₂₇, and its z-translation is 0.

<vertex index="30" size="3">
  5  0.318388  0.55718       0 
  7  0         -0.00536683   0 
  27 0         -0.179829     0 
</vertex/>