Problem: continuous value mapping

Hi guys!

I have a problem with a projection routine that project geometry onto a surface (from a pointview) and yield a ratio between two areas; I've made it work for a single point, but I need it to perform the routine on each middle point of a meshed surface, continuously and seperately (the actual number of vertices is going to a lot higher) - how can I acheive this?

Files are attached if they are of any help (:

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Permalink Reply by David Rutten on April 27, 2014 at 8:12am

Hi 12,

I've taken a different approach, which is much faster, though will not give exactly the same results. You'll have to decide whether you find this other way acceptable. The idea is as follows:

Shoot rays into N random directions, well distributed over a half-sphere.
Count how many (H) of these rays hit an obstacle.
The area factor is then determined by H/N, which gives you values in between 0.0 (none of the rays hit any obstacles) to 1.0 (all the rays hit obstacles).
You can then create a coloured mesh that maps these factors onto a gradient.

The big difference is that instead of accurately measuring the area of the projection of an approximation of the view properties, we're now just dividing the number of hits to the total number of attempts. Both methods use a sampling approach so neither is accurate, but my method doesn't spend a lot of time accurately measuring properties of inaccurate data, which is why it is faster.

Instead of measuring the projected areas, I measure them directly on the sphere. You need to be aware of this difference between your and my logic.

David Rutten

david@mcneel.com

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