When designing a model, first draw a sketch and then restrict it (Eng. Constraint).
In this way, we have the ability to use various methods of constraining, which are already integrated into CATIA software, which greatly facilitate our work.
This function is located inside the SKETCHER module.
In the process of constraining (CONSTRAINT, shown in Figure 1) of some parts of the drawing, it may easily be that the entire sketch is broken, since the process of constraining currently changes the line relationships within the sketch. In order to avoid this, the sketch must be made in the exact proportion, which makes this mode more difficult and unsuitable.
Another way is by using the EDIT MULTI-CONSTRAINT function, which is also located inside the SKETCHER module.
This method is more convenient because we are constraining individual parts of the drawings at the same time, and unlike the CONSTRAINT function, the sketch is updated only when we save the changes. Changes can also be checked by clicking on "Preview".
When we constrain the sketch using the Multi-Constraint function, only those constraint that changes the dimensions is indicated in blue. Once the dimensions have been altered, we can check everything again by clicking on "Preview", or save by clicking "OK". With this function, we can also add tolerances (deviation of individual measures in practice).
Note: If you want to change all dimensions, you need to first click in the empty space around the model, which will deselect all dimensions, otherwise only marked dimensions appear in the Edit Multi-Constraint field.