I am a noob who recently became interest in 3D printing
I downloaded a STL file which i would like to modify and manage to change the object a little bit
However when i wanted to erase a line from the original STL model, the initial STL model disappears, leaving the lines i drew in Sketchup
Is there a way to “auto” draw all the lines on the original STL model?
Also how to i confirm the lines i drew will be “filled” and 3D printed?