How can I find dimension of STL file?

songyi719 · February 6, 2023, 06:56

Hi, I am trying to do some car aerodynamic sim using openfoam, but problem is that stl file of car isn't aligned to be on ground.

Which means, xyz origin of file is somewhere inside the car.

But in order to stick this car on ground (well, cars don't fly) I should place wheel of this car on xy plane, or at least find out z value of wheel surface.

How would I be able to find out such data from stl file?

arjun · February 6, 2023, 07:01

Quote:

Originally Posted by songyi719

Hi, I am trying to do some car aerodynamic sim using openfoam, but problem is that stl file of car isn't aligned to be on ground.

Which means, xyz origin of file is somewhere inside the car.

But in order to stick this car on ground (well, cars don't fly) I should place wheel of this car on xy plane, or at least find out z value of wheel surface.

How would I be able to find out such data from stl file?

There are lots of examples of stl file loaders on net if i am not mistaken. I would just read the stl myself and calculate the center by some C++ or C code.

sbaffini · February 6, 2023, 07:11

You should be able to import the STL in Paraview or Meshlab, find out the bounding box of the STL, notice the zmin of the bounding box and finally translate the STL along z so that z_translation = - zmin.

sbaffini · February 6, 2023, 16:56

Note, however, that this is just the formal answer to your question. This is probably going to give you troubles somewhere along the road, besides being unphysical. It is common instead to have some compenetration between wheels and ground that is more close to the physical reality and better for meshing purposes.

February 6, 2023, 06:56	How can I find dimension of STL file?	#1
songyi719 Member Song Young Ik Join Date: Apr 2022 Location: South Korea Posts: 59 Rep Power: 4	Hi, I am trying to do some car aerodynamic sim using openfoam, but problem is that stl file of car isn't aligned to be on ground. Which means, xyz origin of file is somewhere inside the car. But in order to stick this car on ground (well, cars don't fly) I should place wheel of this car on xy plane, or at least find out z value of wheel surface. How would I be able to find out such data from stl file?

February 6, 2023, 07:11		#3
sbaffini Senior Member Paolo Lampitella Join Date: Mar 2009 Location: Italy Posts: 2,192 Blog Entries: 29 Rep Power: 39	You should be able to import the STL in Paraview or Meshlab, find out the bounding box of the STL, notice the zmin of the bounding box and finally translate the STL along z so that z_translation = - zmin. arjun likes this.

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February 6, 2023, 16:56		#4
sbaffini Senior Member Paolo Lampitella Join Date: Mar 2009 Location: Italy Posts: 2,192 Blog Entries: 29 Rep Power: 39	Note, however, that this is just the formal answer to your question. This is probably going to give you troubles somewhere along the road, besides being unphysical. It is common instead to have some compenetration between wheels and ground that is more close to the physical reality and better for meshing purposes.