In this chapter I’ll show you how to use shading functions and apply different materials. In order to achieve optimal results, it is necessary to deal with certain characteristics of the model itself, to precisely determine how transitions between individual surfaces will be treated. This characteristic is called Smoothing and is one of the key parameters for determining the characteristics of an object.

As an example, I will use the model I created in the first part of the course and immediately enlarge the detail in the middle. As you can see, this bulging surface looks quite natural, although an unusual dark shadow appears near its lower edge. In order to check what it is actually about, I will select this object with one click and then start the Isolate Selection function. In this way, I temporarily removed the rest of the model, so I can check how this element looks from another angle. Now I can definitively exclude the influence of the cast shadow and confirm that the problem was caused by improper “smoothing” of the edges located in the lower part of this object.

In order to show you what its curved surface consists of, I will press the F4 key and thus emphasize the edges that connect individual polygons. In the central part, the transition between adjacent segments will be maximally smoothed, but this principle should not apply to the lower edge, because it represents the boundary between a rounded and a flat surface.

In order to correct this defect, it is necessary to re-apply the function for automatic smoothing (Smoothing), so for this purpose I will go to the Modify panel and check the structure of the entire object. As you can see, it is made of a 3D grid (Editable Poly), so I will immediately switch to the mode that allows me to work with polygons and go down to the section called Polygon Smoothing Groups. In order to be able to activate the option for automatic smoothing (Auto Smooth), it is necessary to first select all segments, and since I already have the Select Object function active, it will not be difficult for me to define a frame that includes all existing polygons with two clicks. After that, I just need to click on the Auto Smooth button and check what I have achieved. As you can see, the black shadow has disappeared, which means that I have successfully solved this problem as well.

You can determine the threshold value that determines whether an edge will be smooth or sharp, and to show you how it looks in practice, I will first cancel the current selection and show the entire object from the side. As you can see, in this zone, the adjacent surfaces are placed at an angle that significantly exceeds the limit value of 45 degrees, because the measurement is made from the outside, and the same applies to the detail located on the bottom side. In both cases, a sharp edge will be applied in that place, which represents the optimal solution.

If for any reason you want smooth transitions to appear on the entire element, simply select all surfaces and set the parameter related to the angle to a high value – for example, 180 degrees. If you then apply the Auto Smooth function again, the program will change the relationships between individual segments, so strange shadows will appear on the screen again.

I don’t like it, so I will repeat the whole process and this time reduce the angle to only 30 degrees. After that, the transitions between individual surfaces will regain the appropriate characteristics, which means that I have chosen parameters that fully correspond to this object.

Before I finish this lesson, I’m going to turn off the mode that allows me to work with polygons and re-render the entire model because I’d like to show you another method you can use to control the smoothness of an element. To that end, I will select the central part of the drone so that, based on the data from the Modify section, I can conclude how different modifiers act on it. In addition, a dark shadow can be clearly seen from its front, which means that this part is not smooth enough. In order to correct it, I will apply the so-called Smooth modifier and place it at the top of the list. To that end, I need to first click on the highest item (Symmetry Y) and then open the complete list and look for the Smooth modifier on it. It will not have an immediate effect because the Auto Smooth option is turned off, so I will take the opportunity to show you how certain details look and then change their appearance with one click. As you can see, currently the value of 30 degrees is selected for the boundary angle, which is quite enough to automatically smooth all transitions.

In the end, all I have to do is cancel the selection and remove all line elements from the screen. This can be most easily achieved by turning off the Edged Faces option, in order to get a much more uniform display in the end.