I'd like to make 3D visualization of a single piece of furniture with a white background, much like in the examples below:
What software, preferably free, would you recommend?
SketchUp => LINK
It has a lot of libraries like 3D Warehouse, where you can build a furniture model with a few steps. Of course it has a "Pro" distro, but you wouldn't need it.
Blender => LINK
This is a powerful free 3D tool, but you would need way more knowledge of modelling than with the SketchUp. Nevertheless, I recommend Blender because of his usage and very nice tools for rendering.
I will disent a bit with the accepted answer. Here is why:
There are several paradigms of 3D applications. Now blender is a DCC application. DCC applications are meant for generating mesh or subd models.
But manufacturing does not work with this constraint. Essentially the standard exchange formats of the manufacturing indusry works on boundary representation models.
So why should you care. Well, if you are making real chairs then this matters a great deal. Since you will find it nearly impossible to work woth other vendors. Maybe you want a hinge, or standard extrusion. Odds are these are available as step models that only really work in boundary representation models. Also if you have a vendor allready, they can provide step files. But usually provide totally unworkable meshes.
Its,a bit like choosing photoshop over indesign for making a book. Sure you can do it.
Now, these dont come in free form except maybe free cad. I would suggest you use Fusion 360, inless you can afford something better like solidworks.
SolidWorks is a very simple and straight to the topic furniture design software. It's supporting a wide variety of materials.
You can use this tool to design virtually any type of furniture components, including desks, chairs, tables, office panels, and customize them according to your needs.
More info about 3d modeling software: https://windowsreport.com/furniture-design-software/
There are many. Almost any software that you can render a 3D model with will do. I'd say if you never used 3D before Sketchup has a less steep learning curve.