d3's built-in clip boundary was causing ugly artifacts during the morph. As the projection transitions from spherical to flat, points near the globe's edge would flicker in and out of the clip region. The fix: manual coordinate projection with custom back-face culling. Instead of letting d3 decide what's visible, I calculate the dot product between each point's normal and the view direction, then fade points smoothly as they approach the horizon. No more flickering. The morph is now continuous and smooth at 60fps — the sphere literally deforms into a flat map without any seams.