Cutting a shape in a solid using a curve, with a non-segmented result — is it possible?
Hello everyone. My question concerns curves which, like the one in the image, are a combination of arcs and straight lines. I know this works in the case of control points curves and interpolate curves, but with these tools it is not possible to draw such a curve (they all result in an averaged, smoothed rounding). Is it possible to transform straight lines and arcs into a logically single curve, without segments? The Rebuild function does not allow me to create an identical representation of the curve.
the screenshot below is an example of what I would like to achieve using the interpolate points tool. Unfortunately, it is almost impossible to obtain a precise curve consisting of straight sections and arcs using this tool.
What is it you are trying to achieve with this method? It is possible to have a single surface with internal G1 tangent joints, but is not recommended, it can cause problems with meshing and downstream processes. What is your goal here?
Chamfering generally involves G0 non-tangent joints. These cannot be made as single surfaces without a lot of trouble and the internal kinks are likely to cause failures in a lot of operations.
surface yes, but that is a bit tricky as @Helvetosaur pointed out. you can merge the surfaces with option smooth unchecked but that can cause issues. also if you extract the edge of these surfaces it will be like the original arc joined with a line.
why do you need exact arcs? is it a mathematical challenge? you can stay within tolerance of arcs but just not use arcs. if you tell us more i am sure there is a solution.
here just to show that you would not notice if you use a control point curve. left side is the split arc surfaces right side was a curve that i derived from the arc but rebuild it as control point to have continous acceleration.
curve:
yes.
_toNurbs will do it.
if the resulting nurbs curve with kinks / multiple Knots makes sense, - same for a surface - is another question.
reverse:
_explode _join
for the surface:
(a) the simplest is to use _loft (splitAtTangent = No) and use the same / copy of the curve twice.
(b) alternative you can play with
_useExtrusions (-> Polysurface)
_creaseSplitting no
reverse:
_DivideAlongCreases
when you use the command on the arc and 2 lines you get again 3 joined lines that can be exploded into 3. the resulting curve also does not create a single cut in a cube.
At the moment, the best solution to the problem seems to be extruding from the curve, then mergeSRF and using this surface trim tool, instead of quick cutting with gumball.
after cutting out a shape in a solid, the topology is transferred to a new shape, in addition along the cutting line, so I then have to modify it (connecting, dividing, new surfaces, etc.) so that the segments run more with surface tension, according to isocurves. In the case of cutting without division into segments, my task is simpler - if segments are needed, I add them quickly, dividing the surface. Red lines - after cutting with segments, green lines - new segments on surfaces added.
