Reflections

Reflections

Reflections show a reflected background across the surfaces of a 3D model.

It is an additional calculation similar to lighting and shading. The reflection may be given as a single texture image, a set of 6 x texture images for "cube mapping", it could be generated in real-time or a ray traced calculation of the lighting and reflections in the entire scene. The higher the realism, the longer it takes to calculate the reflection.

3D Kit Builder

3D Kit Builder uses a simple Texture image as the reflection image to apply to our 3D model. We need an image to use for the "texture" and an image to use for the "reflection". The reflection is calculated using the invisible "normals".

To draw a triangle with texture, lighting and reflection we draw the triangle with lighting calculation first then we draw the reflection as a transparency image blended onto the top of the original triangle.

This is called "multi texture" or "multi pass" drawing because it takes more than 1 pass to draw the triangle. Many 3D graphics systems can now perform this drawing in a single pass, resulting in faster performance.

Turn off Lighting, Texture (Paint) and Reflection in our 3D Kit Builder so we only see the white silhouette of plain triangles on the model:

Display EffectSetting

Texture (Paint)

OFF

Lighting

OFF

Reflection

OFF

Triangles

Now "turn on" lighting for our example model:

Display EffectSetting

Lighting

ON

Reflection

OFF

Triangles with Lighting

Now "turn off" lighting and "turn on" reflection for our example model:

Display EffectSetting

Lighting

OFF

Reflection

ON

Triangles with Reflection

Now "turn on" both lighting and reflection for our example model:

Display EffectSetting

Lighting

ON

Reflection

ON

Triangles with Lighting and Reflection

Further Reading



Cube
Mapping


Reflection
Mapping

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