After we have defined our cameras and views, first step for creating convincing images is setting up scene lighting. Here's how to do this in Rhino.
Before we dive into Rhino’s lighting system, a little theory about what constitutes a daylight and how we can use it.
Basically, a daylight system consist of a sky and sun.
Sky will give us nice soft shadows that help see the shape of our objects.
Skylight comes from all sides equally, and that is why it results in such a finely detailed lighting.
On the other hand, sun light is very sharp, coming from one distant point, and usually doesn’t light up very much, but it provides a good contrast:
See how we can get interesting graphic effects by positioning the sun carefully?
Here’s how the two look together, see how using sun shadow gives a very strong “graphical” diagonal. It also adds a dramatic effect to the image because it looks like sculpture is “hiding her eyes” from the sun. So sunlight is very useful for effects like this (or in case we need to do a real shadow study).
But it’s the skylight that actually helps us understand the space by illuminating the parts in the sun’s shadow, too:
Always use sky to illuminate your scene (at least the daytime scenes).
Use sun only to give accents by shadows.
In other words, for exterior scenes you should always use sky. And sun – you only use it if you want to emphasise the shadows.
Now let’s see how we actually do this.
Turning on the skylight in Rhino is very easy, just click sun icon on Render Tools to open Sun Panel:
Important: Do NOT turn on the sun here! Built-in Rhino Sun is too inflexible and basically useless, so we’ll be making sun “manually” later.
Now if you hit render button (first button on Render Tools panel), you’ll get:
I just told you not to use sun that comes in the Sun panel. You can give it a try, and it comes useful when you need to see accurate sun shadow on a precise time/date and GPS location. However, since we can’t modify the sun intensity or color, it doesn’t work for the aesthetic purposes we need.
So we will create a Directional Light to simulate the sun.
Directional light is a kind of light that gives the parallel shadows (like sun). The position of direction light doesn’t matter, but it rotation does: the rotation of this light type defines the angle that the shadows will fall.
Here’s how to create and rotate the directional light to control the shadow. Note, in order to see the shadows on screen, choose “Rendered” shading type for our view.Note: If you don’t see the light in your view (so you can’t get to rotate it), this is because lights are turned off.
If we render now:
This is not bad, but looks too clinical, because -apart from “sun” washing out the wall on the right side- sun and sky are never so grayscale.
In real life, the color of the sunlight and the skylight changes depending on many factors, most notable the time of the day. Let’s see how light colors typically change during the day:Morning
Afternoon we see both sky and sun move to slightly hotter hues (more red). So sky is now blue purple-ish (very little red) and sun is definitely more orange:
So that was the theory, now let’s see how we adjust these colors in Rhino.
Here’s how to change the color of any light (not only our “sun”), using Properties Panel > Light:
If we render now, we see that the color starts to add life to the image:
Now we only need to change the sky light to make it more blue.
Since in Rhino “skylight” is not a typical light object, we can’t select it and change the color as we would with any other type of light.
Instead we need to change the Environment to affect sky light.
Now we are asked to modify the parameters of the new environment, let’s change name and color:
Now if we render, we see blue hues in the shade, and yellow-orange in the sunlight, which is more realistic for a morning light. We can fine tune these values to get the desired effect to simulate the time of day and atmosphere we want.
With more blue in the sky, and more red in the sunlight, we get a more afternoon feel:
Now let’s see ALL of this in a video (I cut the video at the end because rendering process was a bit slow):
Unfortunately, setting up night-time shots is a bit difficult in built-in Rhino renderer due to it’s limitations. Let’s take a look how a nighttime render would look:
Let’s first try and render the other camera, Pool View, with the same daylight conditions.
See the end of tutorial #1, about Named Views if you forgot how to show the Pool View:
Apart from sunlight angle not really doign this image a justice, we see that the glass objects are as white as anything else. Since we will not get into materials now (and it’s always good to test lighting on a white model first), we’ll just hide the Glass layer and render again:
Now it definitely looks more realistic. Then we will turn off the sunlight:
And now we need to make sky darker.
But what we will do is CREATE ANOTHER ENVIRONMENT first, so we can easily switch between daytime and nighttime sky.
When it comes to artificial lights, there are no solid rules, and all depends on our design and the effect we want to make. Usually it’s good to simulate artificial lighting by adding large rectangular lights pointing downward, just below the ceiling.
Let’s try, and create a rectangular light in the big room, then rotate it downward and move just below the ceiling.
Take a look at the size, rotation, location as well as the color of the light (which we want to be yellow-ish):
Here’s how we got this:
Please note that, as we seen in video, usually the artificial light in Rhino will be very dim, so we need to do two things:
See the following options, play around for best results:
Let’s add another rectangular light just below the ceiling of the pavillion canopy seen in front of our camera view. See the size, location, color and multiplier of this new light:
Here’s what we have when we render:
And unfortunately this is pretty much as far as we can get with Rhino built-in renderer.
You can try to add some spot lights, ideally behind the bench, but Rhino will not calculate them very well, especially because lights don’t have a decay (which is a natural property of light to lose its intensity over distance).
If you want to have more control over lights and better night renderings, you will to use VRay, Brazil, Maxwell or similar rendering package…
If it’s any consolation, if we try to render the other view (the statue) with the lights we have, at least that one will look quite decent (see the Exposure and Tone Mapping options):
Note: To easily access lights, use Lights Panel: