House plans in 2D

I am working on house plans. I want to work in 2D only, and use color for different items in the structure. I would like to be able to draw in multiple overlays. By this I mean I would like to draw wall studs, then draw plumbing superimposed on that, then electric wiring superimposed on that, then drywall superimposed on that; so all are stacked on top of each other, and still be able to make any one or more disappear and re-appear at will, each overlay opaque, and all in 2D.

The real world equivalent of what I want to do would be sheets of paper of various sizes, shapes, and colors all in a pile, and they can be removed one-by-one to see underlying sheets, and then replaced in order.

Everything I have tried either results in Z-fighting shimmering of superimposed colored objects, and/or when I move an object a hole is left in the underlying object, and/or the underlying object is visible thru the overlying object. I have tried grouped and un-grouped objects over or under each other, opening the underlying group for editing to superimpose an overlying object, components, and various TAG setups. All result in z-fighting or hole cutting or or loss of color.

I am aware that I could do much of this by giving each overlay some 3D thickness, but I only need 2D and I have found that working with objects with thickness leads to errors such as pulling a guideline from the wrong edge of a thin object, or an object being out of plane with others.

Using grouping I was able to get partial success. Inside a large rectangle, I drew a medium rectangle touching no edges, then a small rectangle similarly inside that, then painted them different colors. I could move, hide, or delete with no z-fighting or hole cutting. But then I found that if an inner rectangle touches opposite sides of it’s outer rectangle, like a stripe on a flag, then hiding or deleting the stripe cuts the outer rectangle in two.

Any help would be much appreciated. Thanks.

Sketchup is a native 3D environment, if you insist on working in 2D you will be swimming upstream the whole time and fighting against the tool. The workflow you describe would be better suited to a 2D program like illustrator.

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SketchUp is designed as 3D modeling tool. Z-fighting is normal in what you describe. To get around that you’ll need to add some distance between the objects. You can leave them 2D but you’ll need to place them at some small distance from each other.

Probably easier to use something that is intended for the way you want to work.

The advice given by @endlessfix and @DaveR is entirely right. However, it is entirely possible to use SU for 2D drawing so long as you go about it carefully.

What you have described is what we used to call overlays. So for each overlay, you could give everything an overlay Tag. That allows you to switch that overlay on and off easily.

There are at least two ways to get around the Z fighting issue. One is simply to have each overlay a small distance above each other. You wouldn’t see that in plan view. Another would be to select all surfaces and delete them to end up with a wireframe drawing. But you would have to keep doing that. I use an extension called Selection Toys that allows you to filter out lines or surfaces making selecting them much easier. I think you may also be able to use a wireframe Style to do this kind of thing.

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Endlessfix and DaveR:
I should have said that after I have finished my plans in 2D, I will PUSH/PULL them into 3D and then continue in 3D, so I do hope to be able to use SketchUp for the entire process.

simoncbevans:
I followed your suggestion about using tags to do this, and it seems to work well, although it is a bit difficult as you said. I deal with z-fighting by turning off un-needed tags. Then I was able to do the same thing superimposing groups one on top of another, and again only turning on the group I want to see at the moment. I think groups works easier than tags. Using tags requires me to keep one eye always on the pencil icon under the tags heading, to be sure I am drawing on the tag I think I am. Groups are more idiot proof, I can only draw on the group that is visible in front of me.

Thanks to all for your help.

Leave the default tag at Untagged ALL THE TIME.

Only assign tags to groups, components, or non-geometric objects like dimensions, text or section cuts.

ALWAYS draw edges and faces with the tag set to Untagged.

Tags do not separate geometry, only groups or components do.

When you have drawn some new geometry, immediately make it into a group or (usually better) a component. Don’t leave any ungrouped geometry in your model for any longer than it takes to draw it and make it into a component or group.

Perhaps do your blueprint drawings and then group the wall studs, or plumbing, or electrical wiring separately using components or groups (the former is easier as it is clearer), then put them (the groups or components) in different layers, place the groups and components on top of the basic layout of the house then explode all the groups and components.
The layers should still be on the lines and now, they are all one big mess of intersecting lines. After that, look in the Tags tab then turn on or off which ever one you wish to look at.
I know some will talk about keeping everything on the same layer, but if you aren’t going to upload it to the Warehouse for people to use, I’m sure you can do anything to your own model for visualization.

Why explode them? As you wrote, the result will likely be a “big mess” of intersecting lines. Is there some advantage to that mess, compared to leaving the geometry isolated in groups and components? Exploding the geometry into a big connected mess would generally make subsequent modifications to the design (should they be desired) difficult.

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Wow! Just wow!

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@TDahl you’ve a point. After all, the intersecting parts would go to a random layer.
@DaveR hope you like spaghetti.

I just saw this Dave and wish there was a way to like it and say wow and wow again .

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By the way, saying it would go to a random layer just shows a total lack of understanding.

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All of the advice up thru john mcclenahan makes sense to me and I think solves my problem. I draw a floor plan and group it, then draw a wall plan directly on top of that and group it, then draw a plumbing plan directly on top of that and group it. Then in outliner I can turn groups on or off as desired, to view a single plan (no z-fighting) or superimposed plans (tolerating the z-fighting).

For a single room, there is no need for tags. If I have multiple rooms and want to view floor or walls or plumbing for all rooms, then I assign tags for these. So for each room I use groups to view superimposed plans, and for the entire model I use tags to view all floors or all walls or all plumbing. I have uploaded below a simple test model illustrating this.

john: I am inclined to use groups rather that components to do superimposition, as everything must be organized by groups anyway for other reasons, and that all is organized in the outliner. If I used components, my components list would be huge and unorganized and it would be difficult for me to find a component I actually want. Why do you advise that components are better suited for this?

Thanks to all

TEST SUPERIMPOSITION.skp (199.8 KB)

Not so fast wvbirdman!

SketchUp- for some unknown reason - doesn’t render things in sequence, so you see Z-Fighting faces. This is partially functional.

LayOut,on the other hand, will render things in sequence:

  • The component or group that you create First will be rendered “above” the components that were created afterwards.
  • Faces on those other components will therefore be hidden (or partially hidden) if they are obscured by faces on the initial component.

Therefore you will need to draw things in the order of how you want them to appear in LayOut. If you usually draw floors first, then you may need to create an empty component (or group) to put the floor geometry onto.

Unfrotuantely for us, LayOut does not respect Tag sequence - it would be nice if it did!! - so even if you want to use Tag 1 for walls that sit “above” Tag 3 (walls), if the component on Tag 3 was created first, it will be the one to take priority in LayOut.

I don’t know of any other way to re-order the drawing sequence of items in LayOut to move one item (eg, walls) above others (eg floor). …does anyone have any tips/experience on this?

It would make total sense to me if LayOut’s Tags actually worked like…wait for it…Layers!!! (ie, you drag the layer to the top of the stack if you want it to render above the others)

I’m not a frequent or expert user of Layout, but my understanding is that you can sequence and reorder Layout pages in Layers, which unlike SU tags (formerly Layers in SU) DO have a sequence, which you can control by reordering the pages, independently of the order in which they were drawn. Layers ‘higher up’ in the stack overlay and can obscure lower layers.

To avoid Z fighting in SU you can make scenes for different views in SU, using a Wireframe style where different groups might otherwise show Z fighting faces, or instead, just delete faces where they might otherwise cause Z fighting. (Or a mix of the two.)

Reducing the volume of entries in the component browser by making groups instead of components is one of the few advantages of groups. So if that’s your preference, go for it.

I’d still use components myself, because for me having one or even two handfuls of extra components in the Browser for the different sorts of model content is a small price to pay for the other advantages of components vs groups. But you don’t have to agree with me and yours is a perfectly valid choice.

AK_SAM:
Not so fast wvbirdman is exactly correct! I am way too slow to learn Layout. Learning SketchUp to my limited degree nearly killed me.

john mcclenahan:
I will go with groups.

You have helped me a lot on several topics and I am very grateful.

Thanks to all