Reference
SECTION in AutoCAD
How AutoCAD's SECTION (SEC) makes a region where a plane cuts 3D solids, prompt by prompt: 3points, Object, Zaxis, View, XY, YZ, ZX. Try it free online.
SECTION makes a cross-section of 3D solids: a region where a plane cuts each one, and the solids stay as they were. It asks for the solids, until Enter: as in AutoCAD 2027, a set selected before it is dropped and asked for again, what is not a solid is passed over, and a set with none says No Solids, Surfaces or Meshes selected.. Then the plane: by default you give three points on it, and the options give it another way, as at SLICE.
Each solid the plane cuts gets its region, lying in the plane: a block with a hole through it gives the outline with the hole's gap, a cylinder cut along its axis a rectangle. A plane on one of a solid's faces gives that face. One the plane misses says Sectioning plane does not intersect the selected solid.. The regions take the current layer and properties, not the solid's; MOVE takes one out to see it, AREA and MASSPROP measure it, and EXTRUDE turns it into a solid. The whole command is one undo step. MellowCAD's 3D is solids only, and still partial.
- Command:
SECTION - Aliases:
SEC - Panel: Draw
- Try it: Open the editor, type
SECand press Enter.
At the command line
The engine draws it and writes its history as you would type it: the prompts in AutoCAD 2027's order, with the same option letters.
- Command: SECTION
- Select objects: 1 found
- Select objects:
- Specify first point on Section plane by [Object/Zaxis/View/XY/YZ/ZX/3points] <3points>: ZX
- Specify a point on the ZX-plane <0,0,0>: 0,20,0
- Command: MOVE
- Select objects: 1 found
- Select objects:
- Specify base point or [Displacement] <Displacement>: 0,-50
- Specify second point or <use first point as displacement>:
- Command: -VIEW
- Enter an option [Orthographic]: SEI
- Regenerating model.
- Command: VSCURRENT
- Enter an option [2dwireframe/Hidden/Conceptual] <2dwireframe>: H
- Command: ZOOM
- Specify corner of window, enter a scale factor (nX or nXP), or [All/Extents/Previous/Scale/Window/Object]: 0.85x
Options
Object (O)
Takes the plane of an object you pick: a circle, an ellipse, an arc, a 2D spline or a 2D polyline.
Zaxis (Z)
Asks for a point on the plane, then a point on its Z axis, the line square to it.
View (V)
The plane parallel to the screen, through a point you give.
XY
The UCS's XY plane, through a point you give: a point at a height makes a level section there. Enter takes the UCS's origin.
YZ
The UCS's YZ plane, through a point you give; Enter takes the UCS's origin.
ZX
The UCS's ZX plane, through a point you give; Enter takes the UCS's origin. The session's section is this plane through the hole's centre.
3points (3)
Three points on the plane, which may then tilt any way. It is the first prompt's default, so a point there is the first of the three.
What it does not do yet
Surfaces and meshes, which MellowCAD does not have. A planar 3D polyline as the plane's object, which AutoCAD takes. The cuts MellowCAD has no exact form for yet, as at SLICE, which say that one boolean operation failed. SECTIONPLANE and live sectioning, which AutoCAD's ribbon offers in SECTION's place: here SECTION is typed.
What it does and still lacks, in detail (in English)
Questions
How do I make a section of a 3D solid in AutoCAD?
Run SECTION, select the solid and press Enter, then give the plane: ZX and a point through the middle cuts it front to back, XY and a point at a height cuts it level. The region lies inside the solid: MOVE it out to see it.
What is the difference between SECTION and SLICE?
SLICE cuts the solid in two and keeps one part or both. SECTION leaves the solid whole and draws a region where the plane cuts it.
What is the shortcut for SECTION in AutoCAD?
SEC, then Enter or Space.
Why does SECTION say the plane does not intersect the solid?
The plane misses it: check how you gave it. XY, YZ and ZX are the UCS's planes, so a point at the wrong height or side puts the plane outside the solid.