picking right point by mouse clicking
Author
hi,
i need help with selecting points in openGL. I have a reasonable (array)list of vertices, in the amount of 10.000(not any spatial algortithm applied to it).
Now i need to find the nearest/closest point when an user clicks on a location.
I read about the GL_SELECTION part, to create a ray that intersect with plane/ray collision. but how to (quickly) select individual points.
cheers,
P
You can calculate the distance of a point to a ray (or line) using the formula numbered 9 of the description at mathworld.
One way to find the closest point, is to compare the distances of all points to the ray. This brute-force method will perform terrible (esp. with thousands of points). It can probably be optimized by (hierarchically) grouping the points in clusters and performing brute-force only within clusters that are near the ray. This may get tricky though, especially if the points are highly dynamic.
Tom
One way to find the closest point, is to compare the distances of all points to the ray. This brute-force method will perform terrible (esp. with thousands of points). It can probably be optimized by (hierarchically) grouping the points in clusters and performing brute-force only within clusters that are near the ray. This may get tricky though, especially if the points are highly dynamic.
Tom
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