Lighting projectors: adding depth to SL

Updated to reflect the arrival of ALM.

Projectors are a neat way to add lighting effects, reflections, etc., to your Second Life environment. Originally, the relied somewhat on shadow rendering, but then changes made to the rendering system made them easier to use – no active shadows required. With the advent of the Advanced Lighting Model over the more involved deferred rendering options, they became even more straightforward to use.

However, rather than burble on about things, here’s an image of a simple projector in action at my house:

So, how is this done? Pretty simply, actually.

 

First: Enable Advanced Lighting Model

You need to make sure Advanced Lighting Model (ALM) is enabled on your Viewer before actually setting-up your projector. If you don’t, you won’t see anything (nor will anyone viewing your scene – they’ll need ALM enabled).

• Go to PREFERENCES->GRAPHICS
• Find the Advanced Lighting Model option and check it, if it isn’t already checked.
• You may also want to tweak your HARDWARE options – these may not be vital steps, but they may just boost your computer’s performance a little:
  • Turn off ANISTROPIC FILTERING
  • Turn down / turn off ANTIALIASING
• Some systems may prefer it if you disable AVATAR IMPOSTERS and AVATAR CLOTH; I found that on older V3-base viewers, I actually get a slightly higher fps with AVATAR CLOTH off when shadows are enabled (around 5 fps), but notice no real change with AVATAR IMPOSTERS disabled than with them on.

Second: Create a Projector

I emphasise here that I’m only talking you through a very simple projector. How far you go with things is up to you.

• Create a prim. Any prim will do – shape isn’t overly important.
• Click on the FEATURES tab in the Build menu
  • You may have to click on MORE / v (at the bottom of the EDIT menu) to see the tabs
• In the Features tab, there is an option called LIGHT (see below, left)
  • Note that this will only be displayed with all the options shown if you have ALM properly enabled.
• Check the LIGHT option. You should immediately see the area around the prim passively illuminated (below, right). Nothing special here, this is normal behaviour.

• Raise the prim off the ground and the spot effect will be apparent under the Z axis on he prim – projectors only work in one direction.
• Rotate and position the prim for your desired effect and then make the whole thing transparent (and phantom, if it is at a height / location where it it liable to be walked into).
• Done!

Projecting Textures

The projector option also allows you to project textures onto surfaces – this offers a range of opportunities, although a little thought on how you might use them needs to be consider.

To do this, select your projector prim and:

• Click on the second box next to the LIGHT option and click on it to open your texture picker.
• Navigate to the texture you wish to use and click OK to select it.

• The texture will be projected by the prim.

All that remains now is to rotate and position the prim. Here’s my finished example, rotated and projected against a temporary screen.

Additional notes:

• You can change the colour tone for a projected texture by clicking the box closest to LIGHT to open your colour picker.
• You can also modify the look of the projected image using:
  • Intensity: overall intensity of texture – range 0 to 1.
  • Falloff: relative brightness – range 0 (brightest) to 2.
  • FOV: size of the projected image – range 0 to 3 (largest projection) – also influenced by the projector prim’s distance from the surface(s) on which the image is being projected.
  • Focus: focus of the image (hardness / softness) – range -20 to +20.
  • Ambience: contrast of the image – range 0 to 1.

 

Summing-up

How you use projectors is down to your imagination: using rotation scripts, you can generate “spinning” lights and other effects suitable for discos and so on; you can make the prim transparent, you can reduce it in size, you can incorporate it into other items – the list is endless.

For my part, I combined a projector with a “lamp shade” prim and a little bit of scripting so that the table lamp that forms a part of my 1-prim PrimPossible lounge suite will not only turn itself on at dusk and remain on through the “night”, it’ll also cast a pool of comforting light:

Again, remember this is a Viewer effect – so only those who have shadows enabled on their own system will actually see the results of your labours.

Happy playing!

Addendum: in this article I have shadows enabled (my usual mode of running SL. As Ayamo Nozaki note in the comments – remembering this piece was originally written at a time when activating some of the more advanced graphics options was a little more convoluted – shadows *do not* have to be enabled for effects like this.