Create realistic lighting for Games and Movies
Pietro Chiovaro demonstrates the full creation process for achieving realistic lighting
Pietro Chiovaro takes us through the process of creating a realistically lit scene in Blender, with advice on how to use different types of lighting to produce the intended atmosphere
When it comes to creating an environment there are many elements that will help us to achieve a particular effect and a realistic-looking scene. There are arguably three most important elements: firstly there is the contrast between light and shadow, secondly there is the depth of field, and finally there are the imperfections, in the scene and models – like cracks in the walls, dirt, rust, stains and so on – and in the compositing part – like lens distortions, glare and fog.
For example, for this particular interior I chose to give more importance to the centre of the scene, and to do that, I shaded the sides and concentrated the light at the centre.
In addition to this another key element is the way in which every object of the scene is combined. For example, it’s important that the meshes are not duplicated too much and placed in the same place, leaving parts totally empty in the room. At the same time it can also be useful to put a part of the scene in relief – it all depends on the final result that we have in mind. After all, the principal element that can totally change the conception of an scene is surely the light. In fact, thanks to the light, we can give more emphasis to the environment and can completely change the atmosphere of the scene.
01 Concept
The creation of the main concept is the very first part of the process; once you’ve made some sketches and created a planimetry of the structure you will have a clearer view for the creation of the 3D scene. This way you can understand from where the light will come through, so it’s important in this step to define all the possible locations of the lights.
02 Create the 3D environment
At this point you can start to create the 3D models of the interior including all the different objects, furniture, doors, windows and vegetation that make up the scene. For this part the concepts you created in the first step will be very useful as a reference for helping us create a good and faithful 3D environment.
Once all the meshes are placed in the scene, the next stage of the process is to fix the colour management.
03 manage scene Colour
One element that will considerably influence the final look is the colour management of the scene. Open the Scene panel in the Properties window and select Filmic in the Render View inside Color Management. This will give you a huge amount of light information to use, achieving a high dynamic range. Try to render the scene in both Default and Filmic in order to see the difference.
04 take some references
At this point it’s really useful to search for some references of interiors with the light effects we want to achieve. In this case I referenced a render that I did before for another project. However, if you don’t own any photographs with the characteristics you need, you can search on Google and base the reproduction of the lights of your scene on the resources you find.
05 light temperature/colour
When creating lighting through lamps, it's a really important aspect of realism to change the colour temperature of the light. Along with intensity and size, colour is one of the main things that makes lighting look realistic to the human eye. So instead of using plain white light, try using a physically accurate colour based on the type of lighting you're trying to produce.
06 Choose the right lights
Now it’s time to choose the lights for the environment. There are five types of lights in Blender: Point light, Spot light, Directional light (or Sun light), Area light and Hemi light.
For an interior scene like this, I principally used the Point lights for objects like the candles, and a Sun light. I avoided the use of the Area light since this is mainly used in order to simulate the emission of light originating from a rectangular surface (like a TV screen or smartphone).
07 Direct light/sun light
Before we place the lights in the scene it’s important to understand the correct usage of the lights we intend to use. Direct light, or commonly called Sun light, is for the ‘perfect’ simulation of the natural light of the sun – in fact it is produced by a light source at infinite distance from the scene. This type of light occurs in every software; in Blender it is called Sun light.
08 Point light
The other type of lamp that I used in this scene is the Point light. This one is a light that emanates the same quantity of light in all directions (with a spherical emission). In a scene like this it’s useful to light up some parts of the environment, like for the candles, or other parts inside the interior that may look too dark, like the corner of the room or the other room at the side.
09 PLACE the lights
In this scene there are three principal elements where we can place these lights, the two candles on the sides (on the box and at the top of the dresser), and the external light that enters through the windows. For the two lamps on the sides we can use the Point light (given their respective properties). Unlike with the external light, here we don’t want the source of the light to be placed at the origin. We can place another Point light at the centre of the scene to give more emphasis to the central part.
10 hdri maps
HDRI images contain brightness data. Once we have created (through the photographic process) our HDRI map or have bought or downloaded a free map, we need to open the World panel, and in Color select Environment Textures. Now we can import the HDRI maps. If you have speckling on the surface, you can adjust Blender’s Clamp setting in the Render tab (in Sampling).
11 set Parameters
Once we have placed the lights and chosen the HDRI map, we must set them. Go to the Properties window and select the light that we want to set, and here we can change the values of colour, shadow, distance and energy as we prefer. The parameters I set for this light are the following: 100.000 for the Point lights and between 2.000 for the Sun light . As for the colour, I have given a yellowish colour to each light, and for the HDRI map I simply leave it at the default values.
12 mesh materials
Now we can start the 3D wrapping process for every single mesh, creating all the materials and assigning all the textures. At this point by selecting Rendered in Viewport Shading (inside the 3D viewport) we can see a preview of the scene, and if necessary fix any of the parameters of the lights and materials that we’ve already created.
13 emissive material
In the previous step I talked about the creation of materials and the wrapping process for every single element of the project. It’s important for me to underline the way that I create certain parts of the mesh (like the candles) that need an emissive property. In particular, for the flames of the candles I used the Emission Shader linked to the texture of the flame that I created. In this way the flame will not be influenced by other shadows or by the light of the Point light we placed, and instead it will emit its own light.
14 Create A new scene
Another element that is important in the creation of realistic lighting is the use of sun beams. In order to create these sun beams, we need to first go ahead and create a new scene by clicking at the top of the 3D viewport (scene) and selecting the Full Copy option. Once we’ve done this, we can add more ‘density’ to the world.
15 world Density
At this point we need to select the World panel in the Properties window, and by clicking Volume we have to select Volume Scatter and change the parameters of density with a value between 10 and 90. This process unfortunately increases the rendering time but is essential for the creation of this light effect. The lower the value of the volume density, the faster the rendering.
16 Camera focus
To set up the camera focus, you have to select the camera that you are using to render the scene, and in the Properties window, select the panel data (the one with the camera icon). Here you can set the Depth of Field of the camera. In this project I focused the camera to a specific object, in this case the dresser. Another way to set the camera focus is through the Distance value.
17 light Beams
Now we are ready to set the light of this new scene. We need to delete the Sun light we previously created, as we will use a Spot light that will simulate sun beams. We need to place this Spot light outside the room, behind the windows. In order to have clear control over the direction of this light I suggest you activate the Cone by clicking Show Cone in Spot Shape (Spot light properties).
18 render the first scene
Now we need to return to the first scene we made, the one with the Sun light placed in the scene. Here we can start to render the scene and save the final result. To do this, we need to open the Render panel in the Properties window (the first panel to the left). Now we have to set some parameters. I set a 4K resolution for the final render X 3840 – Y 2160 and in the Sampling panel I set a value of 300 for Samples and a value of 1.0 for the Clamp Indirect. The higher the Samples value, the less noise there will be in the final render.
19 render the second scene
Once we have rendered the first scene we can now start the render of the second environment. In this step it’s important to use the same value of resolution that we used in the previous step. This way we can avoid a common proportional error during the blending step. Differently from the previous step I set a value of 1000 samples, since the world density made a lot of noise.
20 Denoiser
Since the second scene will produce a lot of noise, I suggest you activate the Denoiser, a feature of Blender 2.79 that will decrease considerably the amount of noise present in the final render. To activate this feature, you need to open the Render Layers panel and activate the last panel at the bottom of the page, Denoising. You can leave the default parameters since they work pretty well. Of course you can also use this feature in the first scene, even if it will increase the render time.
21 Post-processing
Now we have to start the compositing process, which will give us the possibility to blend the two renders we did before.
To start this process we need to open the Node Editor panel, and here we have to select the Compositing panel, the one to the right of the Shader panel. Now we have to enable Use Nodes.
22 Blend the two renders
Once we have rendered the two scenes in two different images, we need to blend the two renders in order to achieve a sun beam effect. So we need to open the Compositing panel and once we’ve imported the two images, we need to add the Color Mix. Here we need to select the blending type that we want for the final render. In this case I select the Add type and set the Fac. value to 0.100, in order to give more relevance to the first scene, the one without the world density.
23 ADD glare/fog
One of the nodes that will help to give a realistic look to the final render is the Glare filter. In order to use this filter we have to press Shift + Add in the Compositing panel and select Add in the filter section. For this filter I selected the Fog Glow, the High Quality option, a value of 0.600 for the Mix, a value of 0.000 for the Threshold and 8 for the Size. You can set the parameters that will give more emphasis to your scene and that will help you to achieve your desired final look.
24 lens Distortion
Now the last element that I add to the scene is the Lens Distortion. This filter is used to simulate the distortions that real camera lenses produce. For this apocalyptic interior I enabled the Side Projection Mode (projector) and set a value of 0.100 for the Dispersion. Now I run the render again in order to apply all the nodes and see the final result.