Not that I´m hung up on millimeters, but they easily add up in stairs…
I can’t get Layout to measure below 1 mm even though I have set precision to 0,1mm. What am I doing wrong?
You’re setting the precision in the wrong place. Go to Window>Dimension Style and set it there instead. The Units in Document setup have nothing to do with the display of dimensions created with the Dimension tool. Document Setup>Units controls the display of things like distances when moving something on the page.
In order to make any adjustments to dimension precision you need to either have a dimension or dimensions selected or you need to have the Dimension tool active.
ah- thanks.
I have another rookie Layout question:-) Some places its easy to find endpoints (green dot) , while dimentioning a plan, but sometimes I can’t find one, like in the example screenshot. Its the end of a wellformed inner wall component towards the outer wall, but the snap I get is red, on edge.
What version of LayOut are you using? (You still haven’t completed your profile.)
Generally that sort of thing indicates there isn’t an intersection accessible. Perhaps it’s under a section plane or something like that. One thing you could do is put in a pair of crossing guidelines or a guidepoint to dimension to. If you render the viewport as Vector the guides won’t be displayed.
Another option would be to make a Group from slice and use that for dimensioning. Create a viewport for the group and put it on a layer above the floor plan viewport. Dimension to the group from slice. If you don’t want to display that group from slice you can turn its layer off while leaving the dimensions displayed.
its v. 2020 and its under a section plane. II was hoping Layout would find snap-points on intersections with the section plane, as sketchup does. Its more important in Layout than in sketchup, as the floorplans ARE section planes. But I have workarounds now that will last me until Layout 2021. :-). Thanks.
Here’s a quick example of the group from slice thing.
In the perspective view you can see where the group from slice is. That’s where my section cut is for the plan view shown below. I made a copy of the plan viewport to show just the group from slice but it is also displayed in the plan view with the section fill. It’s just not visible.
Usually in LO2020 the Dimension tool will find the intersection but you could have something in the model that is getting in the way. The group from slice will prevent that issue altogether.
on dimensioning my floorplan I have no problems on my outside wall, and not on my inner walls either, except for the ending of my inner wall component towards the outer wall ( They are also components.) I find that a bit strange. But I suddenly had an idea: If I turn off some layers (construction and outer wall) in tags in Layout it will dimension from this end point. I can Reset layers afterwards in the tags list in Layout. Attached is the same inner wall with layers off. I get green “endpoint in model”
so its probably snap “overload” in some places.
Ah, yes. I hadn’t thought that you might have content on layers between the viewport and the dimensions. Of course if you do, those things can get in the way. Best practice then would be to turn off the visibility of all those intervening layers.
I don’t have anything between the viewport and the dimensions, but I found the “Tags” list at the bottom of the “sketchup model” pane in Layout and turned off the complex geometry temporarily…
Its hard though to understand exactly what snaps in Layout represent. The model endpoint (green) on the screenshot in previous post: Is that the intersection of a vertical components edge and the section plane? Or does Layout find my corner of the wall further down into the model at the floor level?
That could happen. I’ve seen weird dimensions because they end up being diagonal lengths. Bottom corner of a wall to the corner of a window. That sort of thing.
One additional thing with the group from slice thing is to turn off all the tags except the one for the slice, do the dimensioning and then go back and turn on the other tags.
yeah. I kind of want to not produce geometry like the section cut that does not update, as I keep changing my model all the time after I have dimensioned it. I keep changing my mind 
Understood. If your model will be changing frequently the group from slice could be problematic. I guess then simplifying the viewport as much as possible by turning off tag visibility for things you don’t need to dimension will help. Fortunately it’s easy enough to turn the tags back on.
I guess if Layout experience problems finding snappooints because of too much geometry, the easy solution would be if you could set some tags, in the tags list in layout, to not be snappable. After all there is only a few layers one wants to connect to. On a plan view it’s just two: the one for inner walls and the outer walls. All other snaps are just potential for error. One does not want layout to find snap points on furniture, or details inside door geometry, or the engineers construction, If one does it this way one can set the viewport properties once and for all, and problem solved