11-14-2017, 11:07 PM
The term is inverted normals. You need to flip the normals outward, and enable backface culling if both sides need to be rendered.
The hotkey for recalculating normals in Blender is Ctrl+N. If there are still tris facing inward, select them and then press W > F to flip those tris outward.
The hotkey for recalculating normals in Blender is Ctrl+N. If there are still tris facing inward, select them and then press W > F to flip those tris outward.