Particle system problem for forest scene

I have hills on my forest scene, and when i use hair to distribute all the trees to the ground, they point wrong direction when they are on a hill. So how can i have all the trees point upwards even when they are on a surface that is oblique.

I tried using the “rotation” panel in the particle settings, and when i click “global y” or “object y”, they start facing upwards but then they all are half into the ground so only tip is able to be seen.

HELP PLEASE! :slight_smile:

The direction the trees point is ultimated controlled by the emitting surfaces normals. If they are pointing down the trees will point down. You can flip the normals by selecting all the verts in the mesh, in edit mode, and hitting w ‘flip normals’

The objects that are being used in the particle system also contribute to their orientation. You sometimes have to rotate the objects, in edit mode, to get them to point correctly.

Your trees need to have their origin at the bottom of the trunk in the center. That is where they will be emitted from.

You can activate Rotation and choose a specific axis for up, like Global Z.