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  1. Lucene - Core
  2. LUCENE-8396

Add Points Based Shape Indexing

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Details

    • New Feature
    • Status: Resolved
    • Major
    • Resolution: Implemented
    • None
    • None
    • None
    • None
    • New, Patch Available

    Description

      I've been tinkering with this for a while and would like to solicit some feedback. I'd like to introduce a new shape field based on the BKD/Points codec to bring much of the Points based performance improvements to the shape indexing and search usecase. Much like the existing shape indexing in spatial-extras the shape will be decomposed into smaller parts, but instead of decomposing into quad cells (which have the drawback of precision accuracy and sheer volume of terms) I'd like to explore decomposing the shapes into a triangular mesh; similar to gaming and computer graphics. Not only does this approach reduce the number of terms, but it has the added benefit of better accuracy (precision is based on the index encoding technique instead of the spatial resolution of the quad cell).

      For better clarity, consider the following illustrations (of a polygon in a 1 degree x 1 degree spatial area). The first is using the quad tree technique applied in the existing inverted index. The second is using a triangular mesh decomposition as used by popular OpenGL and javascript rendering systems (such as those used by mapbox).

      Decomposing this shape using a quad tree results in 1,105,889 quad terms at 3 meter spatial resolution.

      Decomposing using a triangular mesh results in 8 triangles at the same resolution as encodeLat/Lon.

      The decomposed triangles can then be encoded as a 6 dimensional POINT and queries are implemented using the computed relations against these triangles (similar to how its done with the inverted index today).

      Attachments

        1. LUCENE-8396.patch
          82 kB
          Nick Knize
        2. LUCENE-8396.patch
          86 kB
          Nick Knize
        3. tessellatedPoly.png
          20 kB
          Nick Knize
        4. polyWHole.png
          34 kB
          Nick Knize

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            nknize Nick Knize
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            Dates

              Created:
              Updated:
              Resolved: