polygons Archives ⋆ openet.com

Fixing Blender Edges with More Than Two Polygons

In 3D modeling, a mesh’s structure is defined by vertices, edges, and faces (polygons). A non-manifold edge occurs when more than two faces share a single edge. This topology can create problems during various operations such as smoothing, subdivision surface modeling, and 3D printing. Visualize it as a point where three or more sheets of paper meet along a single crease.

Clean mesh topology, free of such non-manifold edges, is crucial for predictable and reliable results in most 3D applications. Issues arising from these edges can range from visual artifacts and shading errors to failures in Boolean operations and simulations. Historically, identifying and correcting these issues has been a vital step in the 3D modeling workflow, and robust tools for this purpose have become increasingly important with the rising complexity of 3D models.

6+ Target Concave Polygons: Issues & Solutions

In computational geometry and computer graphics, a shape defined by a series of connected points can exhibit either convexity or concavity. A convex shape has no internal angles greater than 180 degrees; any line segment drawn between two points within the shape remains entirely within the shape. Conversely, a shape possessing at least one internal angle exceeding 180 degrees is classified as concave. Consider the difference between a simple rectangle (convex) and a star shape (concave). The star’s points create reflex angles, classifying it as the latter.

Distinguishing between these shape types is fundamental in various fields. Collision detection algorithms, for example, often employ different strategies depending on the concavity of involved objects. Concave shapes present greater complexity, requiring more sophisticated methods to accurately determine intersections. Similarly, image processing techniques, particularly those involving shape recognition and analysis, benefit from the ability to categorize shapes based on this property. The efficient rendering and manipulation of complex figures in computer graphics also rely on understanding and processing concavity. Historically, the development of efficient algorithms to manage these shapes marked a significant advance in computational geometry, enabling more realistic and complex simulations and representations.