I have installed the "Drop to ground" addon. I have added the plane and renamed it to "Ground", took a normal cube and put on the plane some distance away from the plane. Then I selected the cube, Shift selected the plane and hit the button to the left - Drop to ground. It's giving an error and nothing is working.

Traceback (most recent call last):
file "C........ addons\object_drop_to_ground.py", line 166, in execute drop_objects (self, context)  
file "C........ addons\object_drop_to_ground.py", line 108, in drop_objects hit_location, hit_normal, hit_index = tmp_ground.ray_cast(lowest_world_co, lowest_world_co+down)  
valueError : too many values to unpack (expected3)  
location : <unknown location>:-1

I have downloaded the addon from this new link https://gist.github.com/mhulse/571947fbe5ca16b7f2b7

Can anybody give me solution for that error

  • $\begingroup$ Similarly to closest_point_on_mesh in blender.stackexchange.com/a/63361/15543 (see comment) ray_cast has an extra return value as of 2.76ish that returns the success of the ray cast blender.org/api/blender_python_api_2_78a_release/… Note: this is also outlined in the gist link comments in your Q. $\endgroup$
    – batFINGER
    Commented Nov 8, 2016 at 13:45
  • $\begingroup$ may i know the solution plz sorry i dont know the language section. may i know what i have to do. can u plz download the addon and tell me whats the solution behind it im using 2.77a $\endgroup$
    – atek
    Commented Nov 8, 2016 at 14:03

1 Answer 1


Object.ray_cast changed in 2.77 to include a "hit" return value giving the success of the hit.

You need to replace lines 108 to 111 with

        hit, hit_location, hit_normal, hit_index = tmp_ground.ray_cast(lowest_world_co, lowest_world_co + down)
        if not hit:
            print(ob.name, 'didn\'t hit the ground')

Full edit here https://gist.github.com/batFINGER/820d385839a222e5a10c1b7f5cdbd0b7

  • $\begingroup$ i have download the zip file. In the zip file it contains folder and in that there is a file drop to ground but it does not have the extension. So i cant install it then i copied the text from the website and save with .py extension it installed successfully but when i click to activate now its give the error Traceback (most recent call last): file "C........ 2.77\scripts\modules\addon_utils.py, line 330, in enable mod=_imprt_(module_name) file "C........ 2.77\scripts\addons\drop ground.py", line 220 register() ^ IndentationError: expected an indented block $\endgroup$
    – atek
    Commented Nov 8, 2016 at 15:33
  • $\begingroup$ Fixed the filename, the indent is ok you may have copied a bit more than the code. Try hitting the RAW button and using select all / copy on that page, or rename the file in the zip, or download zip again. $\endgroup$
    – batFINGER
    Commented Nov 8, 2016 at 15:46
  • $\begingroup$ can u fix the problem for the new version for 2.78 and 2.78a also i have installed but after few 2min it kick me out to the desktop $\endgroup$
    – atek
    Commented Nov 8, 2016 at 16:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .