Before you start creating a 3D model, it would be a good idea to select the display units and adjust the appearance of the auxiliary grid. If you imagine that within your project there is an entire world that has a certain size, it will not be difficult for you to follow the basic rule when creating 3D models: all measurements must be in accordance with the dimensions that these objects have in the real world. In doing so, you can freely choose the appropriate units, which in practice means that centimeters can be used for relatively small objects, while it is better to switch to kilometers for modeling large complexes. If you follow this rule, your models will easily fit into other solutions, and you won’t have problems with other parameters, such as the lighting budget.

To begin with, I will choose the measurement system, which implies the use of the American (in feet and inches) or the metric system (in meters and centimeters). To that end, it is necessary to select the Units Setup item from the Customize menu and open a new frame. After that, it will not be difficult for me to choose the appropriate option and thus use metric, American (US Standard) or another system (Custom). At the bottom of the frame there is another option (Generic) and since it is currently active for me, the entire system will automatically adjust to the sizes I intend to use. Regardless, it would not be bad if I precisely define this relationship, so to that end I will click on the button located at the top of the frame (System Units Setup) and display additional options. Now you can clearly see that one internal unit represents one inch, and this should not particularly confuse you because this parameter is completely independent of the one related to the display unit scale. Regardless, I will choose centimeters from this menu because I would like my models to be fully compatible with other 3D programs such as Maya.

If you intend to create really large models, feel free to choose a larger unit, for example kilometers, but keep in mind that this will directly affect the precision. In other words, the system will automatically be adapted to work with larger objects, where it is possible to subsequently determine the desired precision. This can be achieved by moving this slider, but you should keep in mind that in this case the precision will decrease if the object you are working on is far from the origin. To show you how it looks in practice, I will move the slider all the way to the right and the system will inform me that for this distance the precision will be reduced to one unit (Resulting Accuracy = 1.0). It does not matter whether you use kilometers or centimeters, because the critical distance will always be around 16 million units. I will return this parameter to its previous value, and I would recommend that you select the basic units before you start creating new elements. Otherwise, it may happen that the program automatically changes the size of your model, so it will not match the rest of the project.

I will keep the inches in this frame, but at the same time as the basic system I will activate the first item (Metric) and immediately select centimeters from the auxiliary menu. After that, I can close this frame and continue working because it suits me to enter the dimensions of new objects in these units.

The next parameter that I would like to change is related to the auxiliary grid. It is represented by a series of crossed lines that do not have to be at a fixed distance. To show you how it’s done, I’ll right-click on one of the icons that contain a magnet-shaped symbol and thus display a new frame. After that, I need to go to the section called Home Grid and check the current distance between individual lines. As you can see, it corresponds more to the American system of units (25.4 cm), so I will enter the one unit in this field and press Tab to move to the next parameter. If you pay attention to the display in the background, you will see that the auxiliary network has become much smaller, which means that the system has adapted to new dimensions.

In a similar way, I can set the next parameter (Major Lines every Nth Grid Line) and in that way highlight individual lines. In other words, if I keep the current value for this parameter, every tenth line will be displayed in a different color. Since I would like this area to cover a slightly larger area, I will increase the last parameter (Perspective View Grid Extent) to 30 centimeters, and this will immediately be reflected in the display in the background. If I click on this surface and turn the wheel on the mouse, the entire grid will become a little bigger, so it will not be difficult for me to distinguish the main (Major) and auxiliary lines (Minor).

Considering that I have an active option that serves to automatically adjust the display (Inhibit Grid Subdivision Below Grid Spacing), this enlargement will be very realistic, so at a certain moment only one square will appear on the screen. If I turn the dial in the opposite direction and suddenly reduce the scale, you will notice that some of these lines will simply disappear from the screen, which at the same time means that their mutual distance is no longer just one centimeter, but a much larger distance. The same principle applies to other projections, and in order to prove it to you, I will go to this section and suddenly change the scale, and you will have the opportunity to see how this is reflected on the display of the auxiliary network. At a certain moment, the auxiliary lines will suddenly become the main ones until the moment when it is no longer possible to estimate their distance. In other words, the distance between these two main lines is certainly not only 10 centimeters, regardless of the fact that there are only a predetermined number of auxiliary lines between them.

The opposite effect can of course be achieved by multiple magnification, whereby new elements will constantly appear on the screen until the moment when the grid does not reach its limit values. After that, the spacing between individual lines will remain the same, exactly as much as the Grid Spacing parameter.