KEY FRAMES• A keyframe in animation and flim making is a drawing that defines the starting and ending points of any smooth transition. They are called “Frames” because their position in time is measured in frames on a strip of flim
MORPHING• Transformation of object shapes from one form to another is called morphing.• It is a shortened form of metamorphosis.• It can be applied to any motion (or) transition involving a change in shape.
EXAMPLES• FIGURE: An egde with vertex positions 1 and 2 in keyframe k evolves into 2 connected edges.• Explanation: Given 2 keyframes for an object transformation, we first adjust the object specification in one of the frames so that the number of polygon edges ( or the number of vertices) is same for the 2 frames.
Linear Interpolation• Fig: Linear Interpolation for tranforming a line segment in keyframe into 2 connected line segments in keyframe k+1• Exp: A straight line segment in keyframe k is transformed into 2 line segments in keyframe k+1. Since keyframe k+1 has an extra vertex, we add a vertex between vertices 1 and 2 in keyframe k to balance the number of vertices ( and edges) in 2 keyfranes.
• Using linear interpolation to generate the in- between ,we transition the added vertex in keyframe k into vertex 3’ along the straight line path.
Linear interpolation for transforming a triangle into a quadrilateral• Equalizing keyframes in terms of either the number of edges (or) number of vertices to be addeed to a key frame.• We equalize the edge count and parameters Lk and Lk+1, we denote the number of line segments in 2 consecutive frames.• We define as,
• L max=max(Lk,Lk+1)• L min=min(Lk,Lk+1)• Ne =LmaxmodLmin• Ns=int(Lmax/Lmin)
• Then processing is accomplished by, – Dividing Ne edges of keyframe min into Ns+1 sections. – Dividing the remaining lines of keyframe min into Ns sections.
• If we equalize the vertex count , we can use parameters Vk and Vk+1 to denote the number of vertices in the two consecutive frames. In this case,we define • Vmax=max(Vk,Vk+1) • Vmin=min(Vk,Vk+1) And Nls=(Vmax-1) mod(Vmin-1) Np=int(Vmax-1/Vmin-1)
• Preprocessing using vertex count is performed by – Adding Np points to NIS line sections to keyframe min. – Adding np-1 points to the remaining edges to keyframe min.