Hi Michael,

> Ok, but how do you want me to implement the "nearest neighbor GeomObject method" without running into these very same issues?

Since I don’t know much of anything about the data structures that hold the model in memory, I only have an approximate idea of how one might implement a nearest neighbor method. I infer from your question though that you'd approach it in a way similar to the intersection of the line and other objects. The image I had was of the vector acting like a sort of laser "probe" which would only illuminate the object being intersected: an intersect with a priority. In other words, the vector in the intersect operation acts to select the objects rather than the intersect returning all intersections across all objects within the set. The distance component of the vector would further limit the set of objects. The method would ultimately return the object closest to the vector's origin.

The "cut closest to the curve" part of your idea might be along similar lines.

--Larry

Hi Larry,

re:
> The image I had was of the vector acting like a sort of laser "probe" which would only
> illuminate the object being intersected: an intersect with a priority. In other words,

There are methods like what you describe here used for raytracing renderers.

It's possible to create a type of hierarchical bounding structure around objects such that if the ray intersects an object inside one node of the bounding structure it can know that objects contained in some other further away nodes within the structure do not need to be searched.

But I don't have anything for that already prepared and there is quite a lot of work involved in setting it up and making sure it works properly.


> The "cut closest to the curve" part of your idea might be along similar lines.

It will probably be implemented fairly different from that. Probably something more like it will generate all candidate holes and then only select one to actually use.

- Michael

Hi Michael,

I often wish that I could edit vector graphics in MoI because it has geometric drawing tools that don't exist in graphics editors. I do this a little now, but it's arduous because the layout and layer/group structure of an SVG/AI get destroyed by being imported into MoI and then exported out again as SVG/AI. I end up having to import only 1 layer or group at a time into MoI and then use fiducial marks to get things registered again in a graphics editor.

Keeping some layer or group structure is needed so that things like stroke weight, color, dashes, fills, etc. can be set again when back in a vector graphics editor.

Maintaining layout relative to a page boundary is needed so that layout and dimensions don't change visually or for printing and also to make copy-pasting between vector files easy without going through an alignment and scaling step each time.

It looks like this sort of thing has been discussed before:

http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=9889.3

http://moi3d.com/forum/index.php?webtag=MOI&msg=10774.55

Getting this working probably won't be easy, but it would shave off a bunch of tedious work.

If anyone has figured out a streamlined workflow for editing vector graphics in MoI I'd love to hear about it.

Hi Peer,

re:
> <....>
> Maintaining layout relative to a page boundary is needed

Unfortunately there is a vast amount of work that would be needed to manage a "paper space" environment inside of MoI. I don't expect for that to happen anytime soon, perhaps never.

In general it will work better using MoI alongside a 2D vector graphics program if the data flow is more unidirectional, like you're mainly bringing data from 2D vector graphics into MoI or creating it in MoI and sending it to the vector graphics program. Frequently ping-ponging the same data back and forth is not very workable.

- Michael

Hi Michael,

Thank you for giving a definitive answer.

Hi Michael,

Having closed paths is critical to several common tasks in technical illustration:

1. Closed outline curve so that the outline stroke can be aligned to the outside of the path rather than along center. This avoids having a thick outline overlap the inside of an object which is important when there are fine details along the outline.
2. Hatching clipping mask like for adding a hatch pattern to indicate that a face has been cut by a cross section plane
3. Fills such as block shading like this example:
   
   https://moi3d.com/forum/lmessages.php?webtag=MOI&msg=10770.1
   
   which was made by hand in a vector graphics editor by drawing closed curves and then filling them.
   

Needing closed paths has come up before:

https://technicalillustrators.org/forum/viewtopic.php?f=1&t=211&start=7

http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=6201.61

I've tried out a bunch of different ways of getting from the MoI's SVG/AI output to closed paths, but have found that Illustrator's Live Paint is the only one that works reliably. Several other vector graphics editors claim to have this capability, but they aren't reliable on MoI's vector output because of tiny geometry problems that are essentially invisible. Inkscape is reliable, but sometimes leaves a gap between the closed shape and the line art, and has other problems.

So, it would be helpful if another layer were added to MoI's SVG/AI output. This layer would contain nothing but closed paths.

A few approaches that might work:

• GMIC colorize line art: https://www.davidrevoy.com/article324/smart-coloring-preview-of-a-new-gmic-filter
• Expand strokes into filled shapes, boolean union, extract the resulting closed curves, and then offset them to give some bleed
• Rasterization followed by vectorization like Inkscape “Fill Bounded Area” followed by offsetting to give some bleed. But there are problems with this: https://wiki.inkscape.org/wiki/index.php/A_better_Bucket_Fill_tool_fill

And something like Affinity Designer (low cost) who reload without problem PDF format from Moi3D ?

In any 3D position in the 3D Space inside Moi!

Hi Pilou,

Yes, if MoI generated closed paths then Affinity Designer, Corel, Xara, Inkscape, etc. could use them. Though I was thinking mostly for SVG and AI since it doesn't seem like any most vector software can import PDF layers.

EDIT: Affinity Designer can import PDF layers

- Peer

Ah...I see the problem! :)

Faces are not separated in "projection" ...so we must redraw them manually!
and of course that is not very speedy when there are "curvated" ones and some numerous "projected" intersections!
Not sure that Moi can do that presently...

Hi Peer - Affinity Designer is able to import layers from PDF. That's the only one I know of that does it though.

- Michael

What do you name Layer inside Moi ? (Style? Style of Line ?)

Options PDF inside Moi
What is Prefix & Suffix ?


But i am not sure that resolve the little problem above?

Hi Pilou,

re:
> What is Prefix & Suffix ?

Prefix is something that will get added to the front of the layer name.

Suffix will get added to the end of the layer name.

Some description of this here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=10825.3



- Michael

Ok! It's just labelling something...

And I believe maybe resolve my little problem by just put in front / behind the different layers in Affinity...
I will see that tomorrow!

Hi Pilou,

re:
> And I believe maybe resolve my little problem by just put in front / behind the different layers in Affinity...

Sorry, I'm not understanding - what is the problem?

- Michael

Now I have the different Layers but
Seems there is something with the export PDF
Only one face can have fill color but not sure the geometry is good exported :)


https://moiscript.weebly.com/uploads/3/9/3/8/3938813/hop.pdf
not the the same 3dm but very similar! :)
https://moiscript.weebly.com/uploads/3/9/3/8/3938813/hop.3dm

Hi Pilou,

re:
> Only one face can have fill color but not sure the geometry is good exported :)

Sorry I don't understand what you are trying to do.

Is the fill color something that you're trying to set in a different program? What program is it?

- Michael

I make that only in Affinity! :)
I want just colorized each face separately as shown here https://moi3d.com/forum/index.php?webtag=MOI&msg=10114.476
I have well the 5 Layers but...curious...only the Top Cylinder can be filled and not completely !
(as shown on my previous animation ) https://moi3d.com/forum/index.php?webtag=MOI&msg=10114.484
follow is just theorical schema not the same order and names as above...
(Calque = Layer) I will see that tomorrow evening!
See you soon...

Hi Pilou, in order to get a proper fill in Affinity the path needs to be one combined closed path.

If you select just the layer _faceCyan in your PDF, there are 4 separate unjoined paths that belong to that layer.

You will need to join those together before it will fill properly. If you just select the entire layer with open curves it won't get filled right, it's trying to fill each of the 4 pieces individually.

You can join the curves in Affinity Designer by selecting them all:



Go to the "Node" tool:



Choose the "Join curves" Action here:



Now with it being one single path instead of 4 separate sub paths you can fill it like you wanted:



When the 4 pieces are separate then applying a fill goes like this instead:


- Michael

Thanks for the tip Michael. I've corrected my post above.

Ok better than nothing!

I will continue to explore if there is no trick inside Moi for have direct closed curves! :)

Another thing is maybe a sort of Macro inside Affinity for close all curves inside all Layers!
Because when you have hundred of Layers that is some painful!