The bgl module allows us to obtain various information displayed in 3D Blender view. For example, I made a script that gets the 3D coordinate where the mouse cursor hits a object:
import bpy
import bgl
"""Functions for the mouse_coords_to_3D_view"""
def get_viewport():
view = bgl.Buffer(bgl.GL_INT, 4)
bgl.glGetIntegerv(bgl.GL_VIEWPORT, view)
return view
def get_modelview_matrix():
model_matrix = bgl.Buffer(bgl.GL_DOUBLE, [4, 4])
bgl.glGetDoublev(bgl.GL_MODELVIEW_MATRIX, model_matrix)
return model_matrix
def get_projection_matrix():
proj_matrix = bgl.Buffer(bgl.GL_DOUBLE, [4, 4])
bgl.glGetDoublev(bgl.GL_PROJECTION_MATRIX, proj_matrix)
return proj_matrix
"""Function mouse_coords_to_3D_view"""
def mouse_coords_to_3D_view(x, y):
depth = bgl.Buffer(bgl.GL_FLOAT, [0.0])
bgl.glReadPixels(x, y, 1, 1, bgl.GL_DEPTH_COMPONENT, bgl.GL_FLOAT, depth)
#if (depth[0] != 1.0):
world_x = bgl.Buffer(bgl.GL_DOUBLE, 1, [0.0])
world_y = bgl.Buffer(bgl.GL_DOUBLE, 1, [0.0])
world_z = bgl.Buffer(bgl.GL_DOUBLE, 1, [0.0])
view1 = get_viewport()
model = get_modelview_matrix()
proj = get_projection_matrix ()
bgl.gluUnProject(x, y, depth[0],
model, proj,
view1,
world_x, world_y, world_z)
return world_x[0], world_y[0], world_z[0]
"""drawing point OpenGL in mouse_coords_to_3D_view"""
def draw_callback_px(self, context):
# mouse coordinates relative to 3d view
x, y = self.mouse_path
# mouse coordinates relative to Blender interface
view = get_viewport()
gmx = view[0] + x
gmy = view[1] + y
# draw 3d mouse OpenGL point in the 3D View
mouse3d = mouse_coords_to_3D_view(gmx, gmy)
bgl.glEnable(bgl.GL_BLEND)
bgl.glColor4f(1.0, 0.8, 0.0, 1.0)
bgl.glPointSize(30)
bgl.glBegin(bgl.GL_POINTS)
bgl.glVertex3f(*(mouse3d))
bgl.glEnd()
context.area.header_text_set("hit: %.2f %.2f %.2f" % mouse3d)
class ModalDrawOperator(bpy.types.Operator):
"""Draw a point with the mouse"""
bl_idname = "view3d.modal_operator"
bl_label = "Simple Modal View3D Operator"
def modal(self, context, event):
context.area.tag_redraw()
if event.type == 'MOUSEMOVE':
self.mouse_path = (event.mouse_region_x, event.mouse_region_y)
elif event.type == 'LEFTMOUSE':
bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
context.area.header_text_set()
return {'FINISHED'}
elif event.type in {'RIGHTMOUSE', 'ESC'}:
bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
context.area.header_text_set()
return {'CANCELLED'}
return {'PASS_THROUGH'}
def invoke(self, context, event):
# the arguments we pass the the callback
args = (self, context)
# Add the region OpenGL drawing callback
# draw in view space with 'POST_VIEW' and 'PRE_VIEW'
self._handle = bpy.types.SpaceView3D.draw_handler_add(draw_callback_px, args, 'WINDOW', 'POST_VIEW')
self.mouse_path = []
#self.wx = bpy.context.window.width
#self.wy = bpy.context.window.height
context.window_manager.modal_handler_add(self)
return {'RUNNING_MODAL'}
def register():
bpy.utils.register_class(ModalDrawOperator)
def unregister():
bpy.utils.unregister_class(ModalDrawOperator)
if __name__ == "__main__":
register()
But now I want to get a list with the 2D vertices in screen. How can I get it without having to convert 3D to 2D? If anyone knows, please tell me. Can be the Vertices index too
