Artyom Lebedev

For example, 3DFace vertices, x/y stored only: https://github.com/vagran/dxf-viewer/blob/b7c14a68a78aac9e116b3f6762c026c63392148f/src/DxfScene.js#L785 Vertices accumulation: https://github.com/vagran/dxf-viewer/blob/b7c14a68a78aac9e116b3f6762c026c63392148f/src/DxfScene.js#L2151 Also see all 2D transforms in this file. Shader code assumes 2D coordinates and transforms in buffers: https://github.com/vagran/dxf-viewer/blob/b7c14a68a78aac9e116b3f6762c026c63392148f/src/DxfViewer.js#L564

Looks like QCAD is also not able to display it properly (it displays it in the same was as `dxf-viewer`).  AutoDesk online viewer display it as intended: 

Seems the problem is related to advanced transform from OCS to WCS, i.e. with entity arbitrary elevation and extrusion direction. This feature is not currently implemented.