CtrlE Edge Menu > Bridge Edge Loops does more than you might think.
Just the two loops at the ends were selected to be bridged, here. You could also use the tool to join the tube and the surface its rising from.
Thanks everyone! I now know that i should stick to four points as much as possible and I fixed it! I tried to make a grid on the huge faces and I got rid of as many triangles as possible and I'm very happy with the result :)
Now onto the rest of the guitar!
To follow your approach, you could:
K with C to constrain to the horizontal and Z to cut through.. create loops on both sides,
In Face Mode, Select the inside faces, and CtrlE Edge menu > Bridge Edge Loops
But, if your desk is mainly symmetrical, I would make only one side, and work on that, under a Mirror modifier, with 'Merge' checked.
easiest way is with this addon "Add Mesh Extra Objects".
Once activated in "Blender preferences" > "Add-ons" you can do: "Add mesh" > "math functions" > "regular solid".
Once the object is created, open the configuration (loert left part of the screen) and choose "octahedron" as "source"
Is there a better way to import the files that will give me a cleaner mesh?
This is less a Blender question at this point than a Sketchup question; The import isn't making all the tris, Sketchup is. Perhaps see if there's a "quads" export option.
Assuming that isn't an option (because if it is, you can stop reading), you have two options;
1: Retopologize ...
You have to realize that the reference is from side in orthographic view and from front in perspective. Try to check your model how it looks in perspective. You have to adapt some changes and model it by your guess to make it real, this reference inst good for modeling by exact shape from both views.
Subdivision-surface work best with quads. Triangles and ngons causes artifacts. Checkout this answer. Generally, use quads if you plan on using subdiv.
For example, you can probably form quads in the main body face of your guitar. And if you were planning to use subdiv, you could start off with fewer geometry to form the silhouette. Advice at this point is ...
Looks like you have multiple vertices at the same place. Try merging overlapping vertices by going into edit mode, press A to select all, then go to Mesh>Clean up>Merge by distance. Or press F3 and type "Merge by distance".
Assuming your landscape is a mesh, you may try the following:
add a plane a little bigger than your landscape, and at the base (or lower than) of landscape
with plane selected, and under "modifier tab", you add an "array" modifier. You set to constant offset, X and Y to 0, Z to a distance that suits your needs, and you should increase the count to get as ...
The short answer is that your result is the expected from smooth shading. Forgive me if I cover info you already know here.
A normal vector is a vector that points directly away from a surface. They are used to determine which way a face is 'facing' in terms of how it interacts with light. In Blender, these normal vectors don't always actually point ...
Turning the barrel organ handle -
The handle is animated to rotate.
The right arm hand-bone's 'Pole Target' (in Inverse kinematics) is set to the handle so it is forced to stick onto and follow the handle.
This may not apply in your case, but it would be much easier to copy than to follow:
Select the perimeter of your shape
ShiftD duplicate it and P part it off into a new object
Header Menu > Object > Convert to > Curve
Adjust the curve's bevel in its Data tab > Geometry panel
Convert back to mesh if necessary.