Lighting in Lumion - Mastering Lumion 3D - page 141

An important aspect that we can see on the screenshot is the possibility to tweak the
Cone Angle slider, which in turn controls the area that is covered with this light.
Initially, when we change the Cone Angle slider, there isn't any difference in the area
covered, and the reason is because Lumion doesn't automatically update the light;
we have to either select the light or move it to see the new cone angle. Keep in mind
that the bigger value for the Cone Angle slider, the softer the shadows will be and
the cone angle will lose detail.
The Target light option highlighted in the screenshot is also a useful element to
control the light. For example, you probably noticed that in an art gallery, there is
always a spotlight that points to the painting. With the Target light option, all we
have to do is click with the left mouse button to specify where the spotlight should
be pointing. To finish, click on the Back button to save the final position.
Now, the most important aspect when working with spotlights is the type and
quality we will use. In order to improve the render time, we need to have a balance
between shadow detail and quality.
If we start with the Accuracy option, the shadows created by the spotlight are
updated every single frame. However, what does this mean? Well, if we have a
spotlight with Accuracy turned on and an object is moving, the shadows produced
are real-time shadows. This is obvious, but with the Speed and Memory options, the
shadows produced are static. So, if we have a scene with people walking around, the
quality we have to use is Accuracy ; otherwise, the shadows will not be realistic.
On the other hand, every time we add a light with Accuracy turned on, it is another
shadow that needs to be calculated at every single frame. The shadow has good
quality because a 2048 x 2048 pixel shadow texture is used to create a very accurate
and detailed shadow.
However, if we have a scene without life or a static image, we still have two
other options.
The Speed option provides the perfect balance between render time and shadow
quality because it only uses a static 512 x 512 pixel texture, and the shadow is not
calculated at every frame.