In these 10 tips for better lighting in Cinema 4D, I cover techniques which explore basic lighting concepts and how we can implement these using Maxon’s Cinema 4D.
1. Which type of light?
Depending on the atmosphere you are trying to achieve, choosing the correct light can be fundamental.
For a candle or a light bulb in a room, an omni or point light is the obvious choice so the light emits in all directions. For outdoor scenes, perhaps a light dome or GI for ambient light, then compliment this with an area or infinite light for sunlight.
I tend to use Area lights 90% of the time unless I am after a specific effect. Perhaps an infinite light is more suited for sunlight, but the sun after all is a huge area light that happens to be a very long way away. We can simulate this using an area light, by moving it further away and reducing it’s size, we can control the shadow falloff and give the illusion of parallel shadows.
In this example we have the scene rendered using (from left to right) Default Light, Area Light, Area Light with Area Shadow.
2. Use an appropriate shadow
The type of shadow will strongly influence the feeling of the shot, for a bright sunny day you would want the shadow to be dark and hard with very little falloff, this is in sharp contrast to an overcast day where the shadows will be barely visible as the falloff is so high.
In Cinema 4D we have the option for three types of shadow, shadow maps, area shadows and raytraced shadows. Raytraced shadows are great if you want a cartoon or stylised feel with graphic well defined shadows, the drawback is that they mostly require high anti-aliasing settings to reduce the chatter around edges.
Soft shadows are often used because they give quick results over area shadows, you can fine tune the shadow by increasing your map size and the number of samples. The problem with soft shadows is they do not look very realistic, the hardness or falloff on the edge of the shadow is uniform regardless of distance from the object casting the shadow.
Area shadows are by far the most superior shadow type as they offer high accuracy and the most control. This does come at a price though, area shadows are the slowest to render. To speed things up you can decrease the number of samples and accuracy, this will give you results faster but also will introduce noise.
By adjusting the radius/size of the area in the lights details tab, you can control the sharpness and falloff of the shadows, the smaller the area size, the harder the shadow. In the example below you can see how by increasing the area size, the shadow becomes softer. Note that the area shadow is the most accurate type which you can see with the shadow which will always be hard at the point of contact and then will soften as it gets further from the subject.
3. Multiple lights.
One light alone is rarely going to give you the result you’re looking for as it will leave you with areas in your scene which have no illumination.
A common lighting technique is three point lighting, this uses a main light (key) for the primary illumination, a fill light to illuminate the darker areas, often finished of with the third light, a rim of light from behind to lift the subject away from the background. There are many ways to light a scene or character and three point lighting is fairly basic, but it is still a good technique to master as it can be a good starting point for many shots.
The key / fill ratio is the balance between the intensity of the various lights dictating the overall contrast. If the key light is bright and fill lights are dull, the result is high contrast dramatic lighting such as the full sun of midday. If the illumination of all lights is more or less the same, the result is the opposite and the scene will look flatter, more like an overcast cloudy day.
A good trick is to add a spill light to your scene, this is a light positioned similarly to your key light, however the spill should be much softer and illuminate a wider area, the combo of key and spill creates a more natural look than key light alone.
In this example there are only two lights, a key and a fill light, from left to right, the key becomes brighter and the fill becomes darker showing the effect this has on the scene contrast.
A common lighting trick is to light in layers and have areas of dark move to light and then back to dark to light. This lifts the hero elements away from the background but also allows detail to be seen in the distance. This next render shows how the addition of a rim light will lift the foreground from the background. The render on the right has shadows enabled for the rim light as this removes the unnatural rim on the nose and other areas which should be occluded.
4. Diffuse, Specular and Shadow casting lights.
Although you might be striving for realism, often you may be guided by art direction. Lights can create diffuse illumination, specular highlights and cast shadows, they can do all of this simultaneously or you can disable individual components.
Perhaps your key light position is perfect, but the specular is hitting the wrong spot? You can disable the specular option for the key in the lights general tab, duplicate the light, then enable specular and disable diffuse on the new light. You now have a light which will only create a specular highlight. You can reposition the specular without affecting the key light. Often I will disable the specular on all my fill lights so the primary specular stands out and the subject is not covered with multiple highlights from different directions which tends to look unnatural.
Under the light details tab, there is a checkbox for Shadow Caster, this will turn your light into a shadow casting light only. This can be used in combination with a non-shadow casting light to create the illumination and allows you to reposition the shadow so that you have a more pleasing composition.
In this example I used three lights and pushed the specular high to emphasise the result. In the first render on the left all three lights are contributing a specular, centre there’s no specular and finally on the right, only the key light has the specular enabled.
5. Use light falloff.
In the 3D world a light will illuminate infinitely which is an unnatural behaviour as in the real world, illumination will decrease the further it gets from the light source.
If you enable falloff in your lights details tab, you will achieve a more realistic result as the light will reduce intensity the further it gets from the light source. You should probably choose to use Inverse Square as your falloff type, as this is the most physically correct falloff curve. Cinema 4D offers a second (physically inaccurate) option called Inverse Square Clamped, this uses the inverse square function, but has the brightness clamped to help prevent over exposure.
6. Solo Lights.
As you add more lights to your project it can be difficult to really assess the influence each has on the scene. I like to solo my lights as I build my lighting, this means that I disable all the other lights in my scene and focus on each individual light to refine the illumination and the shadows being cast. If a light is not really contributing anything to the scene then ditch it or move it. There is no point wasting valuable rendertime on lights and shadows which are coincidental. Each light should matter and have a reason for being there, telling a story, just as your composition and staging does.
Here we have the key, fill and rim lights from a simple three point light setup.
7. Coloured lights.
Rarely in the world is a light source pure white, for more interesting lighting use colour with your lights. A popular lighting trick is to use warmer orange colours for your key lights and then use a colder blues for the ambient and fill lights. If you fold down that tiny triangle in the light general tab you can pick your colour using temperature rather than RGB.
Often it will work if you light with complimentary colours for your key and fill lights as these colours will naturally be harmonious. How far you push the saturation of your colour is dependent on the look you’re trying to achieve. For realism, keep the saturation fairly low, if however you’re creating a stylised look then you can push the saturation very high and still obtain pleasing results.
The colour of the lights is essential for portraying a certain time of day or a particular environment. Early morning sun is very different to the harsh lighting of fluorescent tubing. Think of the lighting you’d like to achieve so you have a target in mind and then chase it. Study other 3D renders for reference, and also look at how the old masters worked with light in traditional painting. Artists such as Rembrandt and Caravaggio whose studies of light are an inspiration.
8. Light position and direction.
We already looked at the three point lighting rig and this gives a basic studio result, however, your story is far more complex and exciting.
Think about the environment you’re attempting to recreate and the emotion you’d like to evoke, perhaps it’s a moonlit night with a cool blue from above and a flickering fire off to one side. An early morning with the light low, casting long dark shadows and a deep blue fill from the fading night. Position of your light is fundamental to the story.
9. Linear workflow.
This is enabled by default in your Project Settings and will ensure you’re renders are created in linear color space. In simple terms, the monitor that we work on has a gamma of 2.2, this is so the output of the monitor looks pleasing to the human eye. When you enable Linear Workflow, all elements which contribute to the final rendered image are converted into linear colour space, the renderer processes all images in linear colour space and then finally this is converted back to your chosen colour space / monitor gamma.
What this means is your images will have a more balanced and pleasing look to them. Light and colour will react more naturally and generally it will be much easier for you to achieve a good result than if you had linear workflow disabled. If you want to read more about linear workflow and how it works in Cinema 4D, multipass rendering and compositing in After Effects then here is an article I wrote about this when LWF was first introduced to Cinema 4D.
10. Global Illumination.
If you have the opportunity to use Global Illumination then your lighting should improve simply by enabling the feature. Global Illumination will create secondary bounces of light reducing the need for many fill lights and producing a more pleasing and balanced result in the process. GI can be expensive for render times especially if you’re creating animation and not all projects have the budget for these longer renders. Using the Cinema 4D Physical Renderer combined with QMC Primary and Light Mapping as a Secondary bounce produces a beautiful result, but the renders can be a little noisy unless you bump the samples high enough, at the cost of longer render times.
It is possible to fake GI by using a hemisphere area light or a light dome of some kind, if you combine this with strategically placed bounce lights you can simulate the effect of light bouncing off surfaces. You can download the light dome I use here.
Faking it is never going to be as good as the real thing and rendering with GI does take your creativity to a new level. It is important to remember that lighting is still an important skill and you should not rely on global illumination alone to solve your lighting issues. The shot should still be considered, with each light placement for a reason and all of the tips above are still relevant and should be considered. Lighting is an incredible skill, one that artists can finesse throughout their whole career, it can be so rewarding when you nail that look you’ve been working so hard to achieve.