You upload an SVG, and... chaos. Triangles flying everywhere, holes where they shouldn't be, or just a blank screen. Don't worry, your converter isn't broken. Your SVG just needs a little hygiene.
3D extrusion algorithms are mathematically strict. While a browser can render a messy SVG just fine, a 3D engine needs "watertight" logic.
1. The "Stroke" Problem
The most common issue is trying to extrude a line (stroke) instead of a shape (fill).
The Fix: Convert strokes to paths.
- Adobe Illustrator: Select object >
Object>Path>Outline Stroke. - Inkscape: Select object >
Path>Stroke to Path(Ctrl+Alt+C).
This turns a thin line into a filled rectangle shape that can be extruded.
2. Unclosed Paths
Imagine trying to inflate a balloon that has a hole in it. That's what happens when you try to extrude an unclosed path.
If your shape looks closed but the start and end nodes aren't actually connected, the triangulation algorithm will fail.
The Fix: Use the "Join" command in your vector software to ensure every shape is a complete loop.
3. Self-Intersecting Geometry
If a path crosses over itself like a figure-8, 3D engines get confused about which part is "inside" and which is "outside".
The Fix: Use "Boolean Operations" to merge or cut shapes.
- Illustrator: Window > Pathfinder >
Unite. - Inkscape: Path >
Union(Ctrl++).
Recommended Free Tools
You don't need expensive software to fix SVGs.