How to find a line that is slightly off plane?


Wow what a pain in the a$$ this is.
Been spending more time on fixing the little problems that crop up than making my model.
This kind of BS really makes 3d modelling tedious and unfulfilling.


Forgive me for saying so, but SketchUp’s inferencing system should make it easy to keep everything properly aligned (even accounting for the huge range of what “properly” means in different contexts). This is one of SketchUp’s greatest features. If you pause for about a half-second when positioning the cursor, you give SketchUp a chance to provide feedback if that position is on an endpoint, a midpoint, somewhere along a line, or on a face (i.e., flat plane) or surface (i.e., curved set of adjacent faces), etc. and to automatic snap to positions such as those. SketchUp is “inferring” your intent by performing that snapping adjustment to your position. It works remarkably well.


Yes. It is a pain when you allow the model to get sloppy and out of your control. Fortunately models don’t have to go that route. It’s entirely possible and not at all difficult to stay in control and create clean models. It takes some discipline but the payback is well worth it.


A lesson that many of us have learned the hard way: you may have to proceed a bit slower and more cautiously, but in the end it is faster and easier to avoid getting small errors in your model than finding and correcting them after the fact!


I try to keep things on a plane but sometimes it goes haywire. It isn’t just on tracing lines on a pdf with a line tool and finding they aren’t on a plane when you connect the last dot. It is a bugaboo on some other surfaces when you are drawing stuff after having pulled up the walls, such as ceilings and roofs. Then you find the error has compounded.

And finding where it all went to heck is a trying task. It is difficult to find the out of plane errors, because they can be microscopic. It gets worse when you make changes to the model and find they weren’t on plane.

I really wish there was a tool that would slam the model to 2d prior to pulling up the walls. Or one that changed colors of the off plane line so you could find it easier. I have tried that diagonal line bit and it isn’t always the easiest thing to do. For example, I was trying to find the area of an irregular pond. So I am tracing a photograph of the pond using arcs, and the freehand tool. It was exacerbating to find the out of plane errors.



There are several that can do this. Search the Extension Warehouse and the SketchUcation plugin store for “flatten”.

This is more of a problem because of the computer’s finite precision arithmetic. How far off plane must a line be before it is colored? The existing “color by axis” setting for edges illustrates the problem: it works to within a tolerance and can miss edges that are only a tiny amount out of alignment.


Isn’t this why we use computers? To keep thing correct and true? If a 3D modelling program can’t do that then I am not sure why we are wasting our time with them? I could have been done in a couple of hours with a pencil, ruler and paper.
Just spent 12 hours on my Sunday to work on a project and the last four are not showing up on my project today.
I am afraid Sketchup is not ready for use with the public.


Some of the public certainly.


You’re quite right, pencil, ruler and paper are much more advanced tools to work with than a computer program. You’ll not even be bothered (on paper) with the little mistakes that you talk about when working with SketchUp. For you won’t even be able to find them on your drawing board.
Yeez, stupid programs they make these days.


I agree. These programs are pretty stupid if they are as troublesome as they appear to be.
I thought we were over the era of Windows 95.


It sounds to me as if you just aren’t ready to use a computer to design your projects. That’s fine. There’s nothing wrong with using paper and pencil. It has worked for hundreds of years. Computer aid design isn’t for everyone. But your assertion that SketchUp isn’t ready for the public couldn’t be farther off base.


Thanks for your opinion but I have been using Sketchup for years with little problems so I doubt, I am the problem.
I also want to point out that your comment states the problem with CAD. The AID is left out. When the user has to figure out all of the problems that the computer has not corrected, there is no aid left.
When people are satisfied with a system that does not correct for the human condition, that system is not helping us. It is hindering us.
You want to hide behind that. No problem, but don’t forget that other systems are well on their way supplementing for the human condition.
“Farther off base”, I don’t think so…


Yes, the public that wants to get a job done with ease and not be bogged down with problems and irregularities.
You should check out PLEX. They have a system that works great and requires very little “Fix It” time and is a model for how to make a product for public use.


Oh come on I was going to leave you alone, but if you’ve been using the software for several years and are still having issues with it, the problem is definitely ergonomic.


Based on your comments, it sounds as if you think SketchUp can’t do anything. I have to disagree with you. These were all modeled exclusively in SketchUp without any of the problems you claim exist.

Modeled down to the hardware to create assembly and use instructions.

Detailed to joinery level for construction plans.

Same as above.

And here’s even more complex modeling.


I think perhaps the issue stems from the fact that precision must be set when beginning new models if you haven’t created a local standard template. It’s a very simple concept in program management but probably only learn when sufficient need has become apparent.

Using the program for years is not the same as using the program everyday for years. Sketchup hasn’t advanced enough to know or predict what mistakes you will make. I’m not sure I want it to.


Sorry as I did not realize this post was for their software version. I have used their software version for years. It is their web based product that I am having a lot of problems with.
Sorry for the confusion.
Leave me alone or not, just looking to warn others or fix my problems.

Edit: Misspell.


I think I would try tracing over images using the rectangle, circle, polygon etc tools rather than line tools until I was proficient controlling lines in respect to axis.


I think you are right as I that might be part of my problems with the web app. I realize this post is for the software product. Does anyone know of a tutorial for properly setting up either product to your tastes and creating templates or defaults for these?


Great samples DaveR. You are 100% right.
If we all go through the many tutorials available, take the time to learn it, and we like what we do, SketchUp is a great program. I personally love it. It is the friendliest programs that I’ve ever used.