Editing a floor plan image

What I would like to do, is scan a section of a elevation or floor plan, import it. Then edit ( delete a portion of the image) Example: I import an elevation of the side of a one story building. I want to erase the roof, and draw the walls for the second story addition, the new windows, roof, etc. then save it and print it out.

I don’t want to take the time to trace all of the lines in the bottom half - but just leave them in place. I know, why am I using a 3d program for that? Because I am somewhat facile in it and don’t want to have to learn auto cad.



Make images from each elevation and position them. Scale the lot with the tape tool against a size you know.

Use the stretch and inference tools to make your model…

Make any changes…

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@gadget2020 has one solution but there are others. Maybe the simplest is to edit the image you are using first so that it just shows the wall elevation. If you need the whole thing to create the roof outline, then import both the edited and unedited version and use the edited one to drape over your model. Delete the other once it has served its purpose.

Another option is to use something like Sacn2Cad to create a vectorised version of your scan. That will create lines you can manipulate natively. I have not used it and people do say it tends to create its own set of problems. Just a warning!

Draw the outline of what you want to keep of the elevation image (used as texture on a rectangular face!). Delete what is outside and its rectangular edges. Draw the rest, i.e. your second story and roof adjacent/connected to the “remains” of your image.

In the past I have used similar images as textures on the face of a box, then stretched it, drawn on top of it, pushed & pulled window openings… If I just wanted an outer shell, then I would probably have done it this way.
Instead I started with the floor plan and pulled up the walls, using the elevation drawings as rough height markers (looking at the measurement when it’s stretched by eye, then over-typing in a round figure).

As you mentioned - many ways to do it; no definitive ‘right’ or ‘wrong’ way.

I’ll try this - it seems to address my problem the best. I am attaching a photo, since I have to run to work, but you can see the section. I want to remove the roof and draw the second story. There’s text I need to remove, or relocate etc.

I was thinking also, what if I white outed the stuff I didn’t want, then scanned it, and deleted the back ground then drew my changes?

The other problem which I didn’t mention - if I get a scan of the whole 24 x 36 sheet, is how do I cut the different sections apart, so I can move them?

Ah… OK: Number1 - Sketchup is a 3D modeling package. You actually create a physical model (in virtual space) of whatever you want. That image on a bit of 2D paper is a representation of what it would look like if you cut through it.
SU will show you this, but to print out an annotated 2D image with dimensions and notes (like the scanned in one) you need to use Layout (a program that comes with the full version of SU).

Layout is a flat sheet of paper that you can place views and slices of the SU model onto, then annotate them and print them out.

Again you are thinking in 2 dimensions - any image editing package will let you delete the text, but what you want to do in SU is use this image to grow the building into a 3D Model: trace round the shapes to give a flat “cookie cutter” imprint of what you want and then extrude this into a 3D object.

The other problem which I didn’t mention - if I get a scan of the whole 24 x 36 sheet, is how do I cut the different sections apart, so I can move them?[/quote]
Again, any image editing software will let you copy an area of an image and save it as something else.
Technically you don’t have to - if you use the image to fill a surface, then you can move the image so that the bounding edges of the surface act like a window, only showing you the area you want to see.

Sigh. I guess I didn’t make myself clear in my first post. I know it is a 3d program and I frequently draw 3dstuff. I also frequently draw 2d stuff with it. In this case I don’t need a 3d model.
I just need to find a way to edit an imported image, to delete what I don’t want, and use su to draw my changes.

I really appreciate your long response,

[quote=“Wo3Dan, post:4, topic:25877, full:true”]
Draw the outline of what you want to keep of the elevation image (used as texture on a rectangular face!). Delete what is outside and its rectangular edges. Draw the rest, i.e. your second story and roof adjacent/connected to the “remains” of your image.
[/quote] That is not as easy as it seems. If I understand you, I draw a rectangle, paste the image as a texture there, then outline what I want, then delete the rectangle? I tried it and it worked, see test. I didn’t try to outline the drawing closer, because it seemed a gargantuan task. I saw another thread where Guilly used an image editor to remove the background. Perhaps I could do something like that to do the outline?
With all that text it seems it would be best to make a big box, like I did in the test, and delete the outline.
However, is it possible make the outline disappear without erasing the texture? Or is that impossible?

I appreciate your thoughts on these questions.

I would forget about using the image as part of the entire model and just draw completely new geometry to replace it. It’s not that much and gives you better results. But that is just me.
As for making the outline disappear, yes, you can select these edges and hide them. (see in ‘Emtity Info’). So you would only see the cut out texture part without its surrounding edges. Is that what you mean?

I still think you are mixing up 2D and 3D - you just use the 2D as a reference to build a 3D model:

(Note I’ve not grouped anything - use groups, they are your friends.)
Gerrertw.skp (363.1 KB)
If you want to simply have a 2D drawing, then you are using a screwdriver to hammer in nails.

I really appreciate your taking the time to do the model. The problem is I can’t build from it. That is the single biggest problem I have with doing a 3d model. Applying the visual language of a set of construction drawings to a 3d model. That drawing is one section of a floor, that I am going to do a two story addition. It is attached off the side of a 3 story building. SU is fine for quick concept drawings ( 3/d models ) but it is exceedingly difficult to show the framing details on a 3d model. Or, shall we say time consuming.

Take a look at the walls - they have a hatch for the concrete, another hatch for the insulation, another hatch for the soil around the footings and under the slab, plus the drywall and siding attached to the walls. On a 2d sketch they are easy enough to apply - but on a 3d model? I guess you could bury them in the walls so when you do a section cut they appear.

I have tried to do this with layout, but I struggle with it. Maybe I need to spend more time with it. I dunno. it’s not as intuitive as SU.

So, I realize I am annoying people by using SU to do 2d stuff, and I apologize. I think it can be adapted to that use, and I appreciate the feedback I have gotten along those lines.

Here’s a quick model I did to study the roof line on that same room:


ITs quite logical to use sketchup for 2D stuff. I sometimes do as Well to test construction details.
To quick and dirty Solve your problem try:
1 create a rectangle and paint the texture
2 draw some additional lines to ‘cut’ parts that you dont need. Select what you want to delete and press delete.
3 select the lines you dont want to show. Open window-entity info - and change the visibility
4 select everything and make a group out of it. By doing this, new lines wont mess with the old lines
5 start drawing the additions

NeXT you Will face issues with scaling everything and how to add text but at least this is a start. Good luck!

SU can do what you want, and you can just use it to draw in 2D (but you are better using Layout to print so that it scales properly) however it’s not what it was(/is) designed for.

All current architectural packages work from modelling rather than drawing: all 2D floor plans, sections, elevations, … are taken from specific camera views of the 3D model. This is what the bundled program “Layout” is used for; taking these views and annotating them. You draw in 3D (SU) and annotate in 2D (LO). While it is possible to annotate in 3D and draw in 2D it is more work to get the end results and you might find things don’t quite work as you hoped they would.

Have a look at the Skalp plugin (search for it in the plugin warehouse from within SU) if you want to do fancy things with cut sections.

(BTW you still haven’t quite got the concept of what SU does for you: it is a surface modeler - all you are doing is creating surfaces. If you create a box, it is a bubble shaped into a box - there is nothing inside the bubble. You push and pull at the skin to make shapes, but you are just molding the outer surface to take on the form you want. Each surface can be painted with a different finish (both the inside and outside of the surface). Grouping things into separate bubbles means that they don’t join together when they touch. )

I like that last paragraph. It’s a really clear explanation of grouping. Um. I’ll watch the video and check out the scalping plugin. It’s not that I don’t use 3d, cause I do. I agree, I need to do more grouping, componenting (say nothing of layers) - I tend to draw something, and feel frustrated, sometimes because I am spending more time drawing it then building it. So I become a minimalist. When you think about a house, and all of it’s parts, the walls, floors, ceilings, rafters, stairs, ( say nothing of downloading windows, doors, plumbing fixtures) drawing all of those parts in a model becomes time consuming, and just doing a 2d representation becomes really appealing.

Anyway, thanks. for the advice. G

Wow. I saw two of Sonder’s videos. Simply amazing. Thanks for the reference - I’ll have to watch the rest. I wonder how much time he invested getting to that level of ability? Maybe I’ll give that a go. I’ll have to face the evil demon Lay Out once again. But I have a couple easy projects I could try it with.