angular accuracy limited to 0.1 degrees?

There's a note under the Protractor Tool help topic that says SU "can handle up to 0.1 degrees of accuracy". For civil, land survey, large building, and other large scale work; this seems a bit fuzzy. That's about a quarter foot off for every 100 ft. Not awful, but in some cases too much error.

I wonder, maybe that limit has been improved in SU since that help note was written? Seems like it should be!

The only workaround I've come up with is: rather than entering an accurate angle from a point and a distance to a new point using the protractor, select two (accurate) existing points from which to triangulate the new point. Compute the accurate distances from the existing points to the new point using trig. Then, use circles centered on those existing points, having radii equal to the respective distances you compute to form an intersection where the new point belongs.

I haven't tested it. The method will fail if SU lengths and circle dimensions are limited (i.e., not precise) similar to SU angles.

Anyone have a better idea or explanation for handling angle precision in SU, please?

Stuckfly,

I go into...

"Window > Model Info > Units"

...and change the precision to 0.000°

With this setting (plus a "few" more) I save a new template file, to be automatically used each time I start a new model.

Works for me....

Taff

Your trig suggestion will work but its accuracy is also limited by the number of segments in a circle. The higher the number of segments, the better, but I'm sure there is a limitation there as well.

Just try it and see if you get a better result.

I often have to use extreme decimal accuracy for geodesic dome/sphere construction. For example, I can enter, in the VCB, linear and angular values of at least 6 decimal points (perhaps more - I would have to go back and check to be sure.)

I suspect that the reference to "...up to 0.1 degrees of accuracy" may be in regards to the inferencing system, when angular "snapping" is enabled. I always leave it off, and get 0.000° increments displayed in the VCB.

See if the limitations you noted disappear with a few custom setting changes.

Taff

If you're going to use trig anyway, why not calculate the offset over, say, 100 feet for a given angle? You can specify linear distances in feet to six decimal places. That means you can split an angle into rather small fractional increments. I believe that would be as small as:

arctan(.000001 / 100) = 5.72957795 × 10-7 degrees

-Gully

Oh, I see. Can't enter angle for a line, but I can using the protractor to make a guide and I confirm the angle is dead-on.

Thanks:)

Yeah, I just figured that out after being confused by the endpoint snaps on circles (intersection snap of two circles says endpoint even though it appears it's really the intersection). The limit seems to be 1000 segments, but that makes the snap inference useless. I'm spending more time searching the help forum than I am using the software; not a good sign!

Huh, mine only goes up to 0.0°; must be a Pro version advantage I didn't see in the product comparison table...

True. I have done. Now the bigger problem is all the triangulation measurements I made, since the intersecting circle method seems a bust... Oh well, I have a cheap 2D CAD program I can use to do the linework. Then I can import it to SU to do the modeling. Only, I'm going to see whether CAD programs represent circles using polygons, and if so, I'll see if the "intersection" snap is actually on the circumference or a line segment that approximates a piece of the circumference...

Thanks for all the helpful answers! The SU community might be the program's biggest advantage over other software:)

Stuckfly,

While you can't enter an angle, while drawing a line, you can use the "Rotate" tool to your advantage (skipping the construction line technique.)

Draw your first line (baseline.) Select it, then pick the "Rotate" tool.

Choose the endpoint of the baseline, around which to rotate.

(This is the time you also choose the axis of rotation.)

Choose the other endpoint of the baseline, as angle start.

Press (and release) the <ctrl> key to toggle copy/move.

Rotate copy an arbitrary amount (you don't have to click.)

Enter the precise value in the VCB, and hit <enter>

Technique goes pretty quick, once you've acclimated yourself. If you want to rotate around an axis other than one of the three primary axes, you aren't limited. See how to rotate around any axis of your choosing:

https://sites.google.com/site/sketchupsage/tweak/rotate

Regards,

Taff

(Oh, and we think the SketchUp Group is pretty special, too!)

Stuckfly

Some additional info here

and angular accuracy,

the precceding thread is the one I referred to in this last ref.