The Blender units system is a decimal unit system that can be whatever you want it to be. By default, it's implicitly considered meters. If you go to the scene tab in the properties panel, then to the gravity section, you can see that the rate of acceleration due to gravity is (0.000, 0.000, -9.810). 9.810 is the rate of acceleration in meters ...
You can use the Ruler/Protractor. As of Blender 2.80 the operator was renamed to Measure but it acts like the same way. Good news is that the Measure tool is now directly accessible from 3d View as part of the main Tool Shelf (T) and via ShiftSpacebarM hotkey.
Measure (Blender 2.80) vs Ruler/Protractor (Blender 2.79)
If you hold down Ctrl while dragging ...
The absolute first step is to set the real-world units in the scene tab. This will make Blender's arbitrary units relate to something you can actually measure, like feet or meters.
Lines/Edges that Follow an Axis
You can click on a vertex, press E to extrude, press X, Y, or Z to choose the direction, then type in 1 and hit Enter. This will produce a line of ...
Open the toolbar in the 3D Viewport using T. Navigate to the Grease Pencil section and click the 'Ruler/Protractor' button. You can now click and drag in the 3D Viewport to create a ruler and or protractor measurement.
I recommend using the newer measureit addon instead.
To measure the sum of the length of a bunch of edges like this:
Select the edges
Set the Sum group in Tool Shelf > Measurit > Tools
Click Segment in Tool Shelf > Measurit > Tools
Now the total length of those edges will be displayed at the bottom of the Measureit panel in the ...
If the section of the cut-off happens to be an isosceles triangle, you can simply use Bevel tool to "cut" precisely.
CtrlB to bevel selected edge;
Use Offset as bevel type, the amount is how much you want to cut off the edge.
If both lengths are different, you may consider manually translate or slide one of them after beveling.
Another way to do this ...
By default, 1 BU = 1 meter. Proof: the strength of gravity.
Earth's gravity is about 9.81 m/s2 (or 32 ft/s2, if you prefer) downwards.
Now, if you aren't using any physics simulations, 1 BU can be anything you like, and if you're using physics simulations, then you can tweak the strength of gravity anyway to match with the scale you've chosen.
As well as the ruler and protractor option that was added in blender 2.67, you can also display edge length and angles while you are editing.
In 2.80+ you can find the length and angle options in the viewport overlay options menu.
For v2.7x, you can turn on these options under the Mesh Display panel of the properties region - N
Along with the default 'in Blender' tips already posted, there are several scripts/addons you can use to assist you too. The website Blender3DArchitect has alot of content tuned to this.
The addons are..
- EdgeTools (for 2.63 at the time of writing)
Edge Tools is designed to bring some CAD-style edge-based modeling
tools to Blender. These tools are ...
Simply tick Length under Mesh Display in the Properties side panel and it will show the length of the edges (also tick Area to show the area if there are any faces). These measurements will use the unit specified under Units in your Scene settings. The shown units are local units and are scaled to world units by the object's Scaling settings (see also Why ...
Enable the '3D Print Toolbox' addon.
Open the '3D Printing' tab in 3D view > Tool shelf.
Under statistics, press the Area button. (there's also option for volume and other checks for geometry).
The Addons shelf has been moved on the right of the screen. Press N in the 3D Viewport or click the arrow in the top right of the area to expand it.
When performing any action (such grabbing) that has a number input during the modal operator; you must first press = or NumPad * to enable advanced input for the units.
By default the number input for the modal operators is set to simple, that is why typing in any units after the value does not work.
I would highly suggest everybody reads the release notes ...
Pressing Delete will delete the active ruler (whichever is selected or left-click to select a specific one) before having pressed enter (all the options in the help line are options for during the creation of the ruler).
If you have already pressed Enter you can re-click the grease pencil 'Ruler/Protractor' button to re-enable the rulers and go through the ...
Well, while there might be scripts helping with that, there are at least workarounds:
you can rotate with numerical input, in this example hitting S,-30,RETURN. You can switch on Edge Info >> Face Angle to see what you are doing. And you can rotate around the 3D cursor so you can decide where your center of rotation is (.,, switches back).
An even newer ...
You can set units and scale in the Properties Panel
Newly added cube after scaling to .01m with Edge Info Length enabled:
There are also a few settings in 3D-Views Properties-Panel (N) these influence only the display:
How to model effectively using exact measurements?
How can I use imperial units when entering measurements?
MeasureIt addon also gives the total sum of values.
It's displayed under the measurements list.
Select all the edges you want to measure
Select a "measure group" like 'A' (or it won't work)
Click the Segment button to calculate
You're going to have to first enable an addon in your preferences called Measure Panel.
Next, go to the 3D view and press N. Scroll down to the very bottom and press the activate button on the Measure panel. Check Edge Length, select your edge loop and press Update Selection. The length slider will update with the length of your edge loop.
You could also do a Difference Boolean Modifier. It's fairly straight forward and useful for creating things like holes though solid geometry (windows is one good example).
The great thing here is that it can be done with a few clicks without taking into accounting measuring sides, just position the two objects as you want them to be.
Cube and ...
If you only work with planes or meshes in which all faces have 90° angles between them, following the local object's coordinates, yes (typically planes and cubes which were only rotated in object mode and on which you didn't apply the rotation). You have to apply scale first with Ctrl + A -> scale.
1) Unwrap in edit mode with U, select the cube projection ...
I recently updated an older script that does this:
Rather than poling automatically, you press sum when you need to know the combined lengths, this also takes into account the blender unit settings.
It also has a copy to clipboard function.
fair warning: it reports local measurements only at the moment. ( i should ...
You can't enter an angle directly to define your edge angle. What you can do though is measuring the angle between two edges with the ruler tool.
Just enable the tool in the toolbar (T) in the edit mode and add 2 measurement points: On the first vertex of the first edge and on the last vertex of the second edge by hitting (Ctrl)+(LMB) and dragging your ...
My favorite tool for measuring things is the measureit addon.
Once the addon is installed and enabled, simply enable Show in 3D view > Tool Shelf (T) > Measureit tab. Then select the vertices you want to measure and click Segment. You can edit and delete individual measurements in the Properties Region (N):
If you go to edit>properties>Addons and enable the 3d print toolbox add-on then click on the 3d-print tab on the right side of your viewport you can click volume to get a numerical value for the volume of the object. From there you can either get both volumes and do the math yourself or you can bool the 2 objects and use the 3d-print tools to get the ...
Mesh Align Plus (my addon) was designed to do this. Here's how you measure angles (via GIF, text steps below):
Select/Grab 2 points
Select/Grab another 2 points
Hit "Angle of Lines"
You can get to that panel in the 3D View > Tools Panel (T). Selection order is important (first selected is the "Start" of the line. Also, the points can be anything (mesh ...
To add to the other answers . . .
Another thing that you can do to help you model accurately is to use a unit system other than the Blender unit system. You could use the metric or imperial system. Doing so helps you to remember what distance means.
For example, instead of seeing 13.63 when using the BU system, you'll see 13m 63cm if using the metric ...
By default it uses blender units (BU), which are equivalent to meters. You can specify imperial or metric units in Properties > Scene > Units:
Blender units vs metric
How do blender units and meters, feet, or yards correlate?
What is a sensible scale to work with?