Interior Lighting Using Standard Lights

This lesson will give you a better understanding of the principles associated with CG lighting while also providing some valuable tips and tricks for a faster and more efficient work flow. Moreover the techniques taught in this lesson can be applied to any 3D program used in the industry.

02          In this current scene we are having a really big window on the right side of the scene which can act as the key light source of the scene i.e. the light coming from the direct sunlight. We can have the secondary lights coming into the scene from the other windows and doors on the right which can be the light coming from the day lit outside environment. We will have to figure out the amount of bounce lights and fill lights coming out of the walls and furniture and will need to replicate the effect in some way by just using the standard lights.

03          We will start lighting up our scene by placing a key light i.e. a Target Direct Light just outside the window on the right while placing its target in the center of the room through the window. Switch to 'Front' view-port and move the light up on the 'Z' axis. Bring down its 'Hotspot/Beam' and 'Falloff/Field' value to '38' and '55' respectively while renaming it to 'DFX_Key_Light'. From the 'Intensity/Color/Attenuation' parameters change its color to a light shade of yellow while increasing the 'Multiplier' to '1.5'.

04          Turn on the 'Cast Shadows' option while choosing 'Shadow Map' as the method of calculating the shadows. From the 'Shadow Map Params' increase the 'Size' and 'Sample Range' to '8192' and '10' respectively. After setting up the Key Light in our scene we are now ready to setup the Fill Lights which will define the light bouncing from the four walls of the room. From the top view-port create a free direct in the scene with the name 'DFX_Fill_Light_01' and place it parallel to a wall with its direction into the room.

05          Bring its 'Multiplier' down to '0.7' with a very light shade of yellow as its color. Make sure that the 'Shadows' option is not turned on for this fill light so that it will penetrate the walls easily without casting any shadows. And from the 'Advanced Effects' options turn off the 'Specular' in order to forbid the Fill Light affecting the specular of the objects. Now create four instances of the light forming a circular array surrounding the four walls of the room.

06          Create a copy of one of these fill lights and place it at the top of the roof while renaming it as 'DFX_Top_Fill_Light'. Turn on the shadows of this fill light in order to replicate the soft shadows surrounding the base of the objects where they contact also known as contact shadows. But the roof of the room will act as the obstruction for this fill light so in order to overcome this problem we will exclude the objects 'DFX_Roof_01' and the 'DFX_Roof_Lights_Set' from being effected by this light.

07          Bring down the 'Multiplier' of this light to '0.35' and from the 'Shadow Map Params' bring down the value of map 'Size' to '4096' while increasing the 'Sample Range' value all the way up to '50'. We now need to put in a Bounce light in the scene for which we can create another copy of the fill light while placing it at the bottom of the room. Rename it as 'DFX_Bounce_Light' and decrease the 'Multiplier' value down to '0.25' while leaving the shadow parameter turned off. This bounce light have made the roof in the scene to lit up properly while lifting the overall ambient light as well.

08          Now we will create a secondary light that is caused within the scene from bouncing off the objects and enhancing the effect of key and other light sources. Create an 'Omni' light close to the window in the scene and turn on the 'Ambient Only' option form the 'Advanced Effects' parameters. Rename the light as 'DFX_Ambient_Fill_Light' and change its color to a light shade of yellow while changing the 'Multiplier' value to '0.5'. Turn on the 'Use' option of 'Far Attenuation' parameter and increase the 'End' value to '25.0 Feet' in order to cover most part of the room while decreasing the 'Start' value to '0.0'.

09          Right now our key light is not acting as a key light source, it is just the product of what the light is doing when it hits the geometry surfaces because it’s just a direct light but what we actually need is the emulation of spilling of the key light. So for that we will create an ‘Omni’ light in the right centre of the window while keeping it just inside the wall boundary from the top viewport. Rename this light as ‘Key_Source_01’ while increasing the ‘Multiplier’ value to ‘0.2’. Exclude the window geometry inside the 'DFX_Windows_01' group from being affected by this light.

10          In order to replicate the diffused shadow look coming from the spill of our key light we will create eight instances of this 'Key_Source_01' light, in a form of a circular array while making sure that it covers almost the whole area of our main window. Turn on the ‘Shadows’ option and from the ‘Shadow Map Params’ decrease the ‘Bias’ value to ‘0’ while increasing the ‘Size’ and ‘Sample Range’ values to ‘2048’ and ‘50’ respectively. Turn on the 'Use' option of 'Far Attenuation' parameter and increase the 'End' value to '20.0 Feet' while decreasing the 'Start' value to '0.0'.

11          We are left with three other light sources in the room for which we will create three separate light sources based upon the ‘Key_Source’ omni light bunch. Copy the 8 ‘Key_Source’ lights and place them near to the window on left of the scene using the top viewport while renaming them as ‘Secondary_Source_01’. Place it in the center of the window and exclude the window geometry from being effected by this light. Bring down the 'Multiplier' value and 'Far Attenuation End' value of this light bunch to '0.125' and '8' respectively as this is not the key source of light in our scene.

12          Create two more copies of the 'Secondary_Source' light bunch and place it in the centre of remaining windows and doors in our room. Increase the 'Multiplier' value to '0.1' for each of the light source and adjust the attenuation depending upon the size of the window and door. Exclude the window and the door geometries from being effected through these light bunches by excluding them from their respective light's sollution.

13          As the last and final step select the Fill Lights parallel to the walls and enable the 'Use' function of 'Far Attenuation' parameter. Change the Far Attenuation 'End' value in a way the the light dies after covering half of the room. Also select the 'DFX_Bounce_Light' and 'DFX_Top_Fill_Light' for the floor and roof of the room and give it an 'End' Far Attenuation value of '50' covering the complete height of the room.

14          Before finishing off things here we will try to fine tune the quality of our render a little bit by getting rid of zig zag edges that we are getting as the reflections onto the reflective objects. These artifacts can be avoided by turning on the 'Global Supersampler' from the 'Renderer' tab of the 'Render Setup' dialogue box. Choose 'Max 2.5 Star' from the drop down as it produces some really good results in really less render times when compared to other options.