When placing a light in the scene you'll notice the intensity (or illuminance if using area lights) remains static. This is fine for most things but what if you wanted to create a flickering light source? Flickering lights are an excellent way of building atmospheric tension and it is easily accomplished within Bright Engine.
- Start by placing a new light source in your zone, and make sure its not intersecting with the ground. (You can either increase the Y Pos Modifier before placing the light, or by manually adjusting the Y position after you've placed it. If you already have the light you want to flicker in the scene then you don't need to do this step.
We've also changed the color and increased the intensity a bit for this demonstration.
- We now have a blue light source in our scene which is static. To make it flicker we need to enable Timeline Mode.
- After you do this a few things will happen. Firstly, you'll have two new settings available: Loop Method, and Timeline Length. Secondly your light may have changed color, intensity, radius, or simply outright disappeared. Don't Panic! By enabling Timeline Mode, you have overridden all the settings with Timeline Settings. If you disable Timeline Mode again, your original settings will be restored.
- Starting with Loop Method, you have several options available. Full description of these methods can be found in the documentation. For this tutorials we are going to use the Loop Forward method.
- Depending on which version of Bright Engine you are using, the Timeline Length may be set to zero. This setting determines how long the loop will last for in seconds. Thus we need to enter a value greater than zero for anything to work while using Timeline Mode. For this tutorial we are going use a value of 1 second.
- With those two settings now done, you may notice not much has changed. That is because the Timeline settings need to be set. To do so, we need to open the Timeline Editor. A short cut can be found at the top of the Light Properties Panel.
- In the Timeline Editor we have a list of settings on the left hand side which have been overridden. Lets start by returning the color to what we had before. In our case blue, but you can use any color. To do this double click on the start and end nodes and select the color from the Color Dialog.
If you are unsure about how to use the Timeline Editor, a full description can be found in the documentation.
- If you click back onto the main editor, the light should have changed color as well. Note that you can have multiple colors and create a whole disco scenario if you so wish, but for this tutorial we will stick with a blue light.
- Now lets create the flickering effect. To do so we need to select the Intensity setting. If you are using an Area Light, you should select the Area Illuminance setting instead.
- This setting works just like the color settings, by double clicking on the nodes you can change the color. However, as Intensity is a linear value, all colors are turned to black and white, where black is a value of 0 and white is a value of 1. To create the flickering effect, lets add a few additional nodes with random values and positions.
- Remember that we set the Loop Method to Loop Forward, therefore a smooth transition will no visible skipping, make sure that the first and last node in the timeline are set to the same value.
- The Minimum and Maximum Intensity settings allow you to adjust the overall intensity of the light source. For this tutorial we have set the values to 0.0 and 5000.0. In other words, a black value will have an Intensity of zero, while a white value will have an intensity of 5000.0.
- If you are using large values for Intensity you might find that the light distance is being cut short. This is due to the Attenuation Radius setting. A quick and easy solution is to simply increase the Maximum Attenuation Radius. However, be aware that Attenuation Radius is used to determine the maximum draw distance for shadows. Therefore if this light source is a shadow caster, you can optimise this light by adjusting the Attenuation Radius in sync with light Intensity.
- And voila, You now have a flickering blue light. Why not pair this up with some electrical sparks for a cooler effect?