To be added:
Images
Example tutorial to give people a little experience in entity use.
More info on the entity's variables.
Add links to VDC fixes.
Download containing modified CPP/h. files, compiled binaries and example maps.
Some other stuff.
-----------------------------------------Tutorial So Far---------------------------------------
Dynamic Shadowing and Lighting
Using env_projectedtexture
Information about the entity
<Cool image or two here demonstrating>
Unlike most light entities which lighting and shadowing are calculated during map compiling(VRAD) with a few exceptions(point_spotlight), env_projectedtexture's lighting and shadows are calculated completely in real time and at a per-pixel level. Projectedtexture's use a different method for lighting, which takes the light's point of view and figures that anything the light can't see is in shadow then loads this info into a depth render target(texture). This is a commonly used method called shadow-mapping.
This has some advantages and disadvantages, which I will now go over;
Advantages:
. Lights areas dynamically.
. Allows objects to cast shadows on other objects and them selves.
. Can be parented(after proper code fixes)
. Add depth and complexity to scenes.
. Can "project" a VTF onto a scene.
. Can change the color, shadows, fov, VTF and cast distance dynamically through the entity I/O system.
Disadvantages:
. Objects farther from the light cast shadows with less definition.(Texture resolution limitation)
. Can't be used for large areas, due to the problem above.
. Expensive; having to grab the depth and load it back onto the scene every frame takes slows the whole process.
. Not backwards compatible with older machines.
Okay, now onto the tutorial part, lets learn how to use this thing and where it should be used.
Proper Usage
You must be very careful with this entity, it's not a replacement for every light entity in your map(In fact it won't work as the only light entity in a map and will cause it to be fullbright).
Valve used it for the flashlight and EP2 GMan scenes, something these uses have in common is that the light is extremely close to the caster/receivers. With out the recent code additions from the community, we are limited to only those kinds of usage. With these code additions, we can extend the range to light an entire reasonably sized room. Though without much more drastic changes, we can't light huge areas such as warehouses or outdoor scenes.
Currently(Src07), the Hammer support for this entity is quite little. You can't easily rotate the entity in the viewports and it is missing a keyvalue and input. The code support is also poor. Some information taken from the VDC, credit to relevant authors.
Ideal for this scene(FOV:30, Filter:1, Near-z: 350)
Low near-z(FOV:30, Filter:1, Near-z: 5)
No Filter(FOV:30, Filter:0, Near-z: 350)
High(default Src2007) Filter(FOV:30, Filter:3, Near-z: 350)
High FOV(FOV:60, Filter:1, Near-z: 350)
Per-pixel effect(FOV:100, Shadows: OFF)
ShadowAtten Fading(note the really black part of the shadow near camera)
Missing
Lighting/shadowing fades on brushes not model(note how the airboats are lit but the ground is not)
