Exporting 3D models with dashed hidden lines.Help please!

Hey Yall,
First time poster running into problems dealing with the export of simple 3D objects. For the past while i have been exporting my simple shapes as .obj files and viewing them using online 3D viewers such as p3d.in. this has worked amazingly but i now desire to export with specific shading but i cannot figure it out. All my models right now export as solid smooth faces but i want models that as you rotate, hidden lines and geometry become dashed. its very easy to achieve this in Sketchup itself and i have uploaded a cube test sketchup file for yall to see what im taking about. basically i want my model to still look like that when i export it! I have a feeling this might be a limitation of my online 3D viewer and not an exporting issue at all and if this is the case, is there any other viewers i can use to achieve the desired results? i come to sketchup with a blender background so i am still learning the software. any help would be much appreciated. the link takes you to a sample object on the current online viewer i use, p3d.in.

cube test.skp (78.2 KB)

The hidden lines (Back edges) you see as dashed lines are raster image and not exportable as geometry like you’re hoping.

Thanks for the reply Dave! is there no way around this? i have seen it done so i know it is possible. but maybe outside the scope of program. not sure at this point. i have a screenshot of an example i have seen on the web. the model was actually integrated into the webpage with some sort of plugin i am assuming but the model you see on the image is fully interactive and the the edges become dashed as they fall behind a face.

You can export a raster image or a series of them as in an animated GIF with the back edges visible but you can’t export a 3D model with them as your thread title requests.

I don’t know how the model in your example was made to be interactive but I expect it’s just a series of images. Do you know that the image you show was done with SketchUp? The left mouse button isn’t used for orbiting normally and that simple is not for SketchUp’s Orbit tool.

yeah you are probably Dave about it not being a SketchUp model but i was hoping to achieve the same with SketchUp since it is very user friendly. If it was infact a series of images however i do not believe it would be as interactive as it is (being able to rotate in 3d) .

That’s what my family has called me for as long as I can remember. Well, my mother always called me David, but… :smiley:

How are you planning to use this once you have it set up? Who is your audience? There are some options for making 3D PDFs for example. I think there are some other options as well.

haha meant to write “you are probably RIGHT Dave”. my bad. I am a student at the UofA and a component of my program is a test which is basically various tasks centered around simple 3D objects. To do well, you must be able to visualize the objects in your mind and manipulate them based on the specific task you are given. We are simply creating a tool for our fellow classmates so we can all practice and visualize the objects easier. We have a domain with the practice exams which is why we have been using online 3D viewers (p3d.in) but the audience is only our fellow classmates. hoping to have it passed down each year so everyone in the program can benefit from it! looked a little into 3D PDFs but im not sure if that will be dynamic. because as you rotate an object, lines that were once dashed need to become solid strokes and lines that were once solid will need to become dashed. can you think of any other options that could potentially fulfill this task? thank you!

You’re probably right about the 3D PDFs not working for that reason.

I’m sorry. I don’t know of anything that will. Well, there is the SketchUp Desktop Viewer would give you the option to turn on back edges. The Mobile Viewer might if you’ve save the SU file with the back edges turned on but I haven’t tried that to know for sure.

To get vector line output that mimics the “back edges” display style you can use this workaround:

  • in SketchUp, create two identical scenes, one wireframe and the other in a hidden line style.
  • send the file to LayOut
  • in LayOut, place the wireframe scene on top of the hidden line one and explode it. Then change the linetype of the resulting group to a suitable dashed one.


@Anssi, you’re right. That’s one way to display those back edges in LayOut but it doesn’t help with creating a dynamic, viewer controlled display such that the user can orbit around the model and see those back edges.