Adding Lights

Overview
Required Files
Tutorial

Overview

Lighting in Synthetic Environments contributes significantly to realism and atmosphere. There are a few considerations, however, as lighting in VRML is different to what you may be used to in real-life or pre-rendered 3D.

Individual objects are shaded by lights in the scene but they do not cast shadows on other objects. Usually there is also a limit to the number of lights that video cards can display at any one time. Try to keep the number of lights below 8 - any more and some lights may not be displayed at all and performance will be seriously degraded.

Also, lighting in VRML is calculated from the vertices (corners) of polygons so objects with more polygons will have better shading. Be careful however, as more polygons = slower performance. The developer of Synthetic Environments has to perform a juggling act - almost every decision basically comes down to a compromise between perfomance and quality.

Lights can be one of the following 3 types:

Directional Light	Point Light	Spot Light

The Headlight
The headlight is a single light that is usually on by default. It lights a scene even when you have placed no lights, as is the case with our camera to date, and acts as though you were shining a torch directly in front of you wherever you travel. It is a good policy to deactivate the headlight (see Navigation Info) after you have created some lights, as it often detracts from the realism of your Synthetic Environment.

Required Files

Download and unzip the following file (using WinZip) into the relevant folder of your working directory.

models_background.zip (50.6Kb)

This file contains:

camera_background.wrl

battery_textured.wrl

memstick_textured.wrl

Tutorial

Launch Cosmo Worlds and Open the file camera_background.wrl
Firstly, make sure light icons are going to be visible in your scene - View Menu > Show Special Objects > Show Lights.
Select or to create Directional, Point or Spot Lights then use the DynaBox to move and rotate them into the desired position. Note: Point lights have no rotation controls as light eminates out in all directions from the one point. Also, the position of Directional lights makes absolutely no difference - rotation (direction) is all that counts.
Lighting is a very subtle and personal process. I suggest you add 2 Directional Lights and a Point Light, then experiment with colour, intensities, position and rotation. Try to get a good blend of light, shadow and highlight on the shiny surface of the camera. You can adjust a light's colour and intensity in the Property Inspector.
Your camera may look something like this. It will remain too bright until we deactivate the headlight in a later tutorial.
Save your work.
Preview in Cosmo Player.