how to lay something to the ground

Coding Python Support
1

hi, here I am bothering all of you. Again :smiley:

I would use some suggestion to get (by script) some hollow cylinder, tilt-cut with rounded base, laying on the ground (XY plane). Of course a general procedure, for any shape, would be appreciated

Using images: i would like to get something like that

Immagine.png677Ɨ747 17.5 KB

layed like that

suggestions?

thanks

2

either make it the active object in a rigid body simulation and add a plane as passive object as ground plane

or search the python forums for how to align selection to a face or similar, I remember a couple posts about it

3

thanks guys

@CoDEManX
Iā€™m not familiar with blender simulations. Could you suggest any tutorial or something about it?
Iā€™ll search for the post youā€™re talking about

@RickyBlender, unfortunately the posted suggestions donā€™t work for me
I tried the lieroā€™s script from your linked thread ang I got this

Immagine.png820Ɨ525 38 KB

I also tried the ā€œdrop to groundā€ add-on, but I got this

Immagine2.png829Ɨ598 42.2 KB

4

Hereā€™s the required code:

Just adapt it to use the virtual or an actual ground plane!

Simulation tutorial: https://www.youtube.com/watch?v=rgjvgn9Xm20

5

sorry, maybe i didnā€™t get it: the pointed code is about creating lights normal to mesh faces, how can it be helpful for my case?

6

The math should be applicable for your use case too.

Use the cross vector of 3 vertices you select to get a normal. Calculate a 4x4 difference matrix to Mesh.transform() to desired orientation.

7

then may be you donā€™t have the right question!
looking at your first pic you are not really setting ob on the ground !

it looks like you need to set to ground s0mething but what ?
can you clarify
is it one face or a group of faces or some vert ?
or one face align parallel to another face ?

ounce goal is clear then finding an appropriate solution might be easier!

happy bl

8

@RickyBlender: sorry if I didnā€™t make myself clear. I would like to lay on the ground any object from a starting position as gravity acceleration is acting towards -Z (the overturning moment should be neglected). In the case above the tilt-cut cylinder should rest on the XY plane as shown in the second figure.

@CoDEmanX - Iā€™m not aware ot the math youā€™re talking about. Can you be a little more specific? I would like to learn more about that.

some other questions about the applied-physics-solution:

  1. since I would like to neglect the overturning moment, I have to move way way ā€œdownā€ the center of mass in order to avoid the effect. I figured out it can be done translating ā€œupā€ the mesh. Is some other way, maybe more ā€œelegantā€?
  2. how can I stick to object the translation-rotation reached at the end of the simulation (ALT+A) ? the object always come back to the initial positionā€¦
  3. how can I get directly to the final equilibrium position?