Distance Transparency Ramp Shaders

Distance Transparency Ramp used on the title image.

Distance Transparency Ramp applied to lettering and ground in the title image - note how the “distance” is first from the camera, but on intercepting surfaces on the other side of the object, is the distance from one side of the object to another, leading to some solidity in places in the lettering (no transmission was used, btw, and the ground cube was rendered single sided due to this effect).

What They Do

The Distance Transparency shaders vary the transparency of a surface based on how far away it is.

The shader names below will take you to their parameters section if you click on them.

The Shaders

Distance Transparency Ramp

This shader uses the length of the eye vector as the distance, and varies the transparency of the surface based on that. Normally, the length of the eye vector will be from the camera to the surface, although note that in the case of an object seen through reflection or transmission, it is the length of the vector from the transmitting / reflective surface that is used (which can lead to either useful, or undesired, effects).

Distance Transparency2 Ramp

In order to get around the effects in Distance Transparency Ramp, this shader uses the distance from a preset point, or preset plane. This lets the transparency be based on actual distance from a particular point, irrespective of reflection or transmission etc, but it does mean that the effect no longer follows the camera.

Quick Features and Suggested Uses

1. Cutaways - either version can make cutaway renders of an object, making the near points of an object (or the far points, naturally) transparent. This creates a render where the object retains solidity, but can be seen into. Note that Distance Transparency Ramp will follow the camera, leading to the possibility of animated cutaways with movement of the camera (for the same effect using Distance Transparency2 Ramp, set the “Plane Point” to the camera location, and move / rotate the object rather than the camera!).

2. Materialising Objects - make an object materialise from thin air, fading into view. This can be done by animating the objects position (so could give the appearance of travelling into or out of a portal), or by animating the settings in the shaders (for a static object to fade into place).

3. Unusual Materials - eg for renders of inside the human body, of cells, etc, can use these shaders to control the transparency of surfaces based on how far away they are.

4. Advantages of the Ramps  - The Ramps give even greater control over the effects than previous possible. The area of fade based on distance can be more creatively controlled (it could feature noise in the Ramp, for an uneven fade in area), and “slices” of an object become possible by having having fully transparent up to a certain distance, then fully solid, then back to fully transparent (again, animatable by moving the object, moving the camera, or animating changes in the parameters in the shaders).

Distance Transparency Ramp Shaders Intro

Distance Transparency Ramp ShadersParameters

Distance Transparency Ramp Shaders Tips

TG Pack 3 Index