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With the boundaries now defined, you can establish the mesh over the surface to be tracked. The initial mesh serves as the starting point for tracking, so for best results the mesh should be placed when your surface is as flat-on and closest to the camera as possible.
The mesh can be manually adjusted by dragging current points (multiple points can be moved by holding command and dragging an area around the points) or clicking on an area to place new ones. Option-clicking a point will remove it from the mesh. Manually adding mesh points can be useful if there are flexible portions of the surface known to be a point where the texture should fold but which is not initially identified when placing the mesh. For example, an extended arm may not have a mesh point active at the elbow, but with a mouse click (and a basic knowledge of human anatomy), you can manually add one there. Another use case would be to add points to an area with little detail, but
you know will develop detail as it rotates into view. Placing mesh points in blank areas that show little detail will not improve results and may actually degrade them, so very few points on smooth areas is desirable. A good rule of thumb is that if more than five points are created inside the boundaries, the mesh may be good enough for tracking. Points cannot be added or deleted after tracking.
A good mesh is a sign of good tracking as they go hand in hand. If your mesh has few points detected and the results don’t track tightly, you can artificially improve your results. For example, make sure that the content is clearly visible. Tracking and point detection can fail if the surface is too bright (HDR), too dark, or low contrast due to working in log. To improve results, you can add a corrector node before the Surface Tracker to adjust contrast and levels manually, then run the Surface Tracker. You could also use a corrector node with the Contrast Pop effect before the Surface Tracker to help track surfaces that are too smooth. In both cases simply disable the corrector node again after the tracking has finished.
— Regenerate Mesh: This button recreates the mesh at the current frame and settings and discards any manual changes that have been made.
— Point Locations: These controls determine which mode is used to generate the mesh points.
— Automatic: The Surface Tracker automatically locates the best details for tracking, and places mesh points on those details. In most cases Automatic will give you the best results.
— Point Number Limit: Lets you set the maximum amount of mesh points to place. The number of mesh points affects how the overlay will flex and fold, and should be set by the expected flexibility of the surface. They do not directly affect tracking speed.
— Minimum Point Spacing: Lets you set the minimum distance between mesh points. This prevents mesh points from bunching together too tightly in highly detailed areas and interfering with each other.
— Uniform Grid: Creates a regular grid of points in the boundary and relies on internal shape models to deform the grid during tracking. This may give better results than Automatic mode if your surface is highly detailed.
— Horizontal Spacing: Adjusts the horizontal distance between adjacent points in the uniform mesh.
— Vertical Spacing: Adjusts the vertical distance between adjacent points in the uniform mesh.