Feature Request: Place/move added parts by "jogging"  

Why are you attempting this sort of thing in the slicer?  It belongs in CAD and, frankly, the slicer would be improved by the removal of such CAD-like features that only serve to confuse newbies.  Removing the links to Printables too would reduce the frequency of users attempting to modify sub-par models by skipping the CAD phase.

Cheerio,

RE:

Please explain how I create a negative volume in CAD. Obviously, this would be a feature in "Expert" mode only.

RE:

Also, in the more general case, i.e., where I might have an STL file of an object but not the CAD file, I  won't, in most cases, be able to import the STL file back into (my) CAD program to modify it there, so it more-or-less HAS to be done in the slicer. In addition to negative volumes, removing CAD features from PS would negate such helpful features as adding modifiers with its seven options including the handy (currently) 17 gallery shapes, all of which would benefit from a more intuitive (IMHO) method of placement.

P.S. Printables, Thingiverse,  et als, do not always include CAD files which you may or may not be able to open or import.

RE: Feature Request: Place/move added parts by "jogging"

Would some sort of "snap-to" (face/edge/corner) feature be more workable? IANAP, but somehow I think it would be a nightmare to program such a beast. Willing to be proven wrong. 

RE: Feature Request: Place/move added parts by "jogging"

To be more precise, yes, it's possible to create negative volume in (most) CAD programs. I was thinking more of a "stand-alone" or generic/amorphous shape that I might want to modify an existing STL file with, for which I  have no original CAD file for. Slicer to the rescue.

It's fundamental to most CAD applications, add and subtract primitive solids - or add and subtract elevated drawings.  Most do the job with interactive, possibly parametric, graphics but for illustration I will use a scripted method, the following is OpenSCAD code:

difference(){
  cube([50,50,10]);
  translate([25,25,0]){
    cylinder(r=20,h=10);
  }
}

It generates the difference between a 50mmx50mm cuboid and a 20mm radius cylindrical rod centred 25mm from both the X & Y axes, the cylinder therefore acting as a negative volume and cuts a hole through the cuboid:

Like this.

Cheerio,

RE: Feature Request: Place/move added parts by "jogging"

What are OpenSCAD's import options? I.e., if all I have is an STL file of an amorphous organic shape, can I bring it into OpenSCAD and put a hole thru it using your example?

RE:

What are OpenSCAD's import options? I.e., if all I have is an STL file of an amorphous organic shape, can I bring it into OpenSCAD and put a hole thru it using your example? If not, how would I accomplish that?

RE: Feature Request: Place/move added parts by "jogging"

Amorphous?  The bigger and more detailed the model (the more triangles) the more memory and time will be used so yes ...

but for a quick and dirty example I looked on Printables for something I might use over Christmas - Printables is almost useless nowadays but I found a part uploaded today, downloaded the stl and decided to pair it with a knight silhouette that I already had on file:

// from:  https://www.printables.com/model/1116273-sorting-tray-for-jigsaws/files 

import("/root/jisawsortingtray.stl");  // note designer's spelling

translate([200,0,0]){
  difference(){
    import("/root/jisawsortingtray.stl");  // second copy
    translate([-50,-450,0]){
      linear_extrude(height=10){
        import("/root/knight.svg");
      }
    }
  }
}

translate([350,-450,0]){
  linear_extrude(height=10){
    import("/root/knight.svg");   // second copy
  }
}

 The straight download is on the left, the cutting shape at right and the result centre.

The odd translate value is because the silhouette file includes a wide border that I had to skip.

Note: The file-path format inside the quotes will vary according to your operating system.

Cheerio,

RE:

May I inquire as to which CAD program you downloaded the STL file into? By what metric do you consider Printables "almost useless"? What assemblage of downloadable 3D printing files would you recommend as being more useful?

May I inquire as to which CAD program you downloaded the STL file into?

That's still OpenSCAD

By what metric do you consider Printables "almost useless"?

It's essentially unsearchable, there are no quality metrics other than 'Likes' which are self reinforcing and frequently hide better files, and there is no way for an inexperienced user to know whether or not a 'Printable' file is actually printable.  Worse, Prusa are integrating it into the slicer without addressing these issues.  It was already losing value three years ago before Prusa gamified it and now it has grown ten times larger and many more times worse.

There are several thousand really good files on Printables, buried under nearly a million entries that are useful to no-one.

What assemblage of downloadable 3D printing files would you recommend as being more useful?

For general files? there are none.  Some manufacturers maintain useful spares-files databases for their products.  As far as I can remember that tray is the first Printables file I have downloaded this year with the intention of printing it - but now I realise I deleted it after posting above; no matter, if I do decide I want one I can probably redesign from scratch faster than rummaging for it on Printables...

Cheerio,

RE: Feature Request: Place/move added parts by "jogging"

I agree with Diem on the fundamentals.  Just differ in the CAD package of choice 🙂  Modifying existing stl files to do such things as negative booleans is very easy in Blender and it already has precise placements, as well as all the snap to options. 

That along with either wireframe or transparency modes makes placing cutters to remove bits simple.  Something also requested in PS years ago.  Also the boolean difference (the negative modifier function in PS) has various options that can be selected to alleviate some of the potential issues when you have verts that coincide.  

Even other modifiers are easier to position in cad and then export to PS as one model, do a split to parts and then change specific parts as type modifier then apply the modifications to slicing settings for those.  That way they are already pre-positioned where you need them

RE: Feature Request: Place/move added parts by "jogging"

Oh goodie, I'll just take a couple of months off to learn Blender, neither easy nor an efficient use of the remaining time in my gerontolicity. Problem solved. I now disengage. 

RE: Feature Request: Place/move added parts by "jogging"

Blender has this reputation of being difficult to use. While that may have been true year’s ago, it is certainly not the case now. 
it’s had massive constant development. It shouldn’t take more than a couple of hours to learn the basics of moving stuff around and doing a Boolean.   
I found it more difficult to learn Fusion and unless you are already a programmer it is also easier than openscad. Although with a few YouTube tutorials even that is doable. 

While you can spend years learning all the things it’s capable of doing, for basic modelling and manipulation of existing meshes there are few tools that compare. Meshmixer  maybe for manipulation. 
I don’t think you have that many more years over me Reddawg lol.
The way I look at it is like this, the time spent learning a useful tool works out to less than I’d spend fiddling around trying to do something in the slicer. 

Just differ in the CAD package of choice

Most CAD software can do it but in general with reduced facility.  The STL is a bunch of triangles, often a huge number of them, describing a surface.  Imagine an STL describing a sphere - it is much less manipulable than a CAD sphere described as a point and a radius - so STL reworking is usually cumbersome and if at all possible the original CAD file should be preferred.

Cheerio,