Non-manifold geom was producing inverted result when the camera was inside
the shadow volume.
When rendering non manifold geometry with the depth fail method, we need to
emit the cap as if it was the same geometry with a virtual thickness.
Another way to view it is to imagine having a set of non-manifold geometry
all facing the light.
So for every tri we emit a front cap oriented toward the light and the
back cap pointing away from it (whatever the actual orientation of the tri).
Extrusion pass stay the same as the depth pass method (double the increment
if it's a manifold edge).
In the Python API, any panel becomes a subpanel by setting bl_parent_id
to the name of the parent panel. These subpanels can contain advanced or
less commonly used settings.
Now hairs are shaded properly in workbench and support texturing.
I also added a 10% random normal direction per hair to have a bit more
variation in the shading. This is hardcoded for now.
This is a dirty fix. A bit more cleaner approach would be to check if a
context is bound and delay the deletion only in this case.
Also we may want to do this orphan deletion at some other places than
wm_window_swap_buffers.
Do note that it does not match cycles implementation.
Also we could precompute the hash per strand before rendering but that would
suggest it's not per engine specific.
If we make the random value internal to blender then it won't be a matter
because other renderers will have access to the same value.
This is really convenient for development. Either for profiling the
generated shaders or to check if the generated code is correct.
It writes the shaders to the temporary blender session folder.
(ported over from blender2.8)
By default when moving a edge of the screen it always snaps to an invisible grid with unit of 4 pixels.
This was also affecting the snap to the midpoint and adjacent.
The solution was to make the snap to areagrid optional and use values of `origmin` and `origsize` that match the transformations in screen_edit.c.
