A hair model contains semi-transparent textures to simulate dense hair. To render these textures correctly, the material property `writesToDepthBuffer` is set to `false`.
However this causes hair polygons that are further away from the camera to cover hair polygons that are nearer to the camera. This results in an artefact line that you can see in the Xcode Scene Editor on the top edge of the blue sphere that is a placeholder for a head inside the hair model.
For the hair that is covering the sphere, the hair is rendered as expected. For the hair that is not covering the sphere, the hair from polygons further back are rendered, causing a "texture break" to appear at the top edge of the sphere.
How does the renderer settings or the model have to be changed to avoid this "texture break" on top of the sphere?
Screenshots if the issue here:
