I usually use Tinkercad to add details that I don’t know how to draw in Sketchup Web, but when I export the model as an STL file and import the file into Tinkercad, parts of the model have collapsed into triangular distortions. I looked inside the model on Sketchup and did not find any extra lines that could account for the distortion. Is there any possible explanation for why this happens? If so, is there anything that I can do to fix the problem?
The model looks like this on Sketchup:
But when I import it in Tinkercad, this happens:
It also happened with a model that I downloaded from the 3D Warehouse and tried to modify in Tinkercad.