Once we have a sequence of pathlet states, we have a sequence of associated pathlet models and we can generate a new trajectory in the appearance parameter space.
For each pathlet model, we can generate a new pathlet. The generated trajectory in the appearance parameter space is the concatenation of the pathlet generated from each group in the order it appears in the pathlet model sequence. We have two ways of generating the pathlets given a model. We can use the spatiotemporal model of pathlets (equation 5.6 in section 5.3.2) or we can use the spatiotemporal model with linear residuals (equation 5.8 in section 5.3.3).