qgsvectorlayerprofilegenerator: Fix intersection for collinear polygons#66432
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ptitjano wants to merge 1 commit into
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qgsvectorlayerprofilegenerator: Fix intersection for collinear polygons#66432ptitjano wants to merge 1 commit into
ptitjano wants to merge 1 commit into
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ptitjano
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rouault
reviewed
Jun 10, 2026
| vl = QgsVectorLayer("PolygonZ?crs=EPSG:3857", "polygon", "memory") | ||
| self.assertTrue(vl.isValid()) | ||
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| polygon_wkt = "Polygon Z ((547405.88 6150237.19 0, 547405.88 6150237.19 5, 547413.39 6150203.24 5, 547413.39 6150203.24 0, 547405.88 6150237.19 0))" |
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those "random" looking coordinates are difficult to reason with. If there was a way of coming with simple looking coordinates, that might help (no strong requirement, just asking in case it is not too difficult)
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No strong opinion. I just tried to stay in line with other unit test which use similar "random" coordinates.
troopa81
reviewed
Jun 11, 2026
With tolerance at 0, when a triangle from the tessellated polygon is collinear In the XY plane, the `processTriangleLineIntersect` worflow does not work and a special case is requirede. In that case, the intersection between the profile line and the profile line is computed. For every intersection, the Z value is extracted. For each intersection, a Z value is calculated along the edge. The lowest and highest Z values are then used to build the vertical profile segment represented by the triangle. This changes fixes 2 issues when iterating over the triangle edges: 1. Use the triangle, instead of the input polygon is used to compute intersection 2. Preserve the first valid intersection point when processing collinear triangles. Otherwise, a subsequent failed edge intersection test may overwrite a previously valid intersection point, causing profile segments to be skipped.
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Description
With tolerance at 0, when a triangle from the tessellated polygon is collinear In the XY plane, the
processTriangleLineIntersectworflow does not work and a special case is requirede.In that case, the intersection between the profile line and the profile line is computed. For every intersection, the Z value is extracted. For each intersection, a Z value is calculated along the edge. The lowest and highest Z values are then used to build the vertical profile segment represented by the triangle.
This changes fixes 2 issues when iterating over the triangle edges:
AI tool usage
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Example
Bug
Fixed