A very popular effect being applied to 3D Rooms is the illusion of a shiny reflective floor. This illusion is achieved by creating a mirror version of the room geometry and applying it directly under the floor, and then adjusting the transparency of the floor texture between them. When done right this is a very striking effect, but there are some pitfalls that are specific to this effect in IMVU’s 3D engine.
Here are a few tips and things to avoid when building a reflective floor in your rooms and bundles
Is My Avatar a Vampire? 
The room in the example above is as good as it gets as far as reflective floors are concerned. The illusion is enhanced by the beautifully textured furnishings and the dramatic lighting of the walls.
The only problem is that the most important addition to the room, your Avatar, is not reflected at all. This is because this is not actually a reflection but a nearly completely transparent floor looking down into a reverse version of the room below.
No matter how effective the trick, until we have actually reflective surfaces in IMVU, the avatar will never appear in the “reflection”. 
In this example you see an equally dramatic reflection effect, although under closer inspection, the room below is not actually a complete copy. There are several areas of the reflection that differ from the main room.
As dramatic as this effect is, it can be over used. If the floor texture is set too transparent then it can become hard to distinguish where the floor actually is, causing the virtual equivalent to vertigo. Also, it is important to remember that any furniture added to the room will also not reflect, so the more objects that are not reflecting in the floor surface, the less effective your illusion will be.
In some cases a duplicate copy of a furniture item can be placed and rotated under the original to create a faux reflection… but if that item includes seat nodes then the avatar will be able to click and sit (upside-down) on the duplicate furniture.
Is There Something Worth Reflecting? 
Reflective floors are also most effective when there is something in the architecture of the room that is worth reflecting. Arches, pillars, windows, and other details work well.
In the example above it is nearly impossible to relate to the space since the floor texture is nearly completely transparent and there are few recognizable interior elements to help you relate to just where you are in the space.
Hide That Reflected Room
When building additional geometry under the floor of a room, it is important to hide the space as much as possible.
IMVU’s 3D Camera does not include collision detection with surfaces like walls, so it is very easy for the camera to pop in and out of the walls of your room. If the lower room is visible from outside the space then it will appear as a strange second floor, and confuse your customers as they try to navigate the environment.
When you build a reversed room, be sure to include a black box to house it within. This can be geometry that has its one-sided Normals facing out, completely enclosing the space.
Although technically the 3D Camera could accidentally pop below the surface of the floor, it is less likely then a customer seeing the “hidden” room from outside the walls of the space would be. 
Something to keep in mind…
The black void that surrounds 3D objects in IMVU isn’t exactly “black”, so it is worth taking a little extra time to try and match the color of your concealing box so that it blends in perfectly with the surrounding void. Go Have Fun…
… but use a little restraint. Although a cool effect it is not without problems that can take away from the illusion your are trying to achieve. Here are some things to think about:
- Make sure your Room has something it is worth Reflecting
- Hide the geometry of the “reflected” room as best you can.
- Avoid completely transparent floors since it can confuse your customers. A little opacity is better then not enough.
- If your room includes furnishings, try to include them as part of the Room AND the reflection. If you are building a bundle, consider placing upside-down copies of each item under the floor. If you are placing furniture that includes seat nodes then use your discretion as to whether the effect is worth the unpleasant surprise of finding your avatar upside down under the floor.