5.5 KiB
Materials: Commands
deformvertexes
Syntax
deformVertexes
Overview
This command performs a general deformation on the surface's vertexes, changing the actual shape of the surface before drawing the shader passes. You can stack multiple deformVertexes commands to modify positions in more complex ways, making an object move in two dimensions, for instance.
Functions
wave
Designed for water surfaces, modifying the values differently at each point.
It accepts the standard wave functions of the type: sin, triangle, square, sawtooth or inversesawtooth.
The "div" parameter is used to control the wave "spread" - a value equal to the tessSize of the surface is a good default value.
normal
This deformation affects the normals of a vertex without actually moving it, which will effect later material options like lighting and especially environment mapping. If the material stages don't use normals in any of their calculations, there will be no visible effect.
Design Notes: Putting values of 0.1 to 0.5 in Amplitude and 1.0 to 4.0 in the Frequency can produce some satisfying results. Some things that have been done with it: A small fluttering bat, falling leaves, rain, flags.
bulge
This forces a bulge to move along the given s and t directions. Designed for use on curved pipes.
move
This keyword is used to make a brush, curve patch or model appear to move together as a unit. The x y and z values are the distance and direction in game units the object appears to move relative to it's point of origin in the map.
The func base amplitude phase and freq values are the same as found in other wave form manipulations.
The product of the function modifies the values x, y, and z.Therefore, if you have an amplitude of 5 and an x value of 2, the object will travel 10 units from its point of origin along the x axis. This results in a total of 20 units of motion along the x axis, since the amplitude is the variation both above and below the base.
It must be noted that an object made with this material does not actually change position, it only appears to.
Design Note: If an object is made up of surfaces with different materials, all must have matching deformVertexes move values or the object will appear to tear itself apart!
autosprite
This function can be used to make any given triangle quad (pair of triangles that form a square rectangle) automatically behave like a sprite without having to make it a separate entity.
This means that the "sprite" on which the texture is placed will rotate to always appear at right angles to the player's view as a sprite would. Any four-sided brush side, flat patch, or pair of triangles in a model can have the autosprite effect on it. The brush face containing a texture with this material keyword must be square.
Design Note: This is best used on objects that would appear the same regardless of viewing angle. An example might be a glowing light flare.
autosprite2
Is a slightly modified "sprite" that only rotates around the middle of its longest axis.
This allows you to make a pillar of fire that you can walk around, or an energy beam stretched across the room.
Notes
Specific parameter definitions for deform keywords:
This is roughly defined as the size of the waves that occur. It is measured in game units. Smaller values create agreater density of smaller wave forms occurring in a given area. Larger values create a lesser density of waves, or otherwise put, the appearance of larger waves. To look correct this value should closely correspond to the value (in pixels) set for tessSize of the texture. A value of 100.0 is a good default value (which means your tessSize should be close to that for things tolook "wavelike").
This is the type of wave form being created. sin stands for sine wave, a regular smoothly flowing wave. triangle is a wave with a sharp ascent and a sharp decay. It will make a choppy looking wave forms. A square wave is simply on or off for the period of the frequency with no in between. The sawtooth wave has the ascent of a triangle wave, but has the decay cut off sharply like a square wave. An inversesawtooth wave reverses this.
This is the distance, in game units that the apparent surface of the texture is displaced from the actual surface of the brush as placed in the editor. A positive value appears above the brush surface. A negative value appears below the brush surface.
The distance that the deformation moves away from the base value. See Wave Forms in the introduction for a description of amplitude. SeeWave Forms in the introduction for a description of phase)
See Wave Forms in the introduction for a description of frequency)
Design Note: The siv and amplitude parameters, when used in conjunction with liquid volumes like water should take into consideration how much the water will be moving. A large ocean area would have have massive swells (big siv values) that rose and fell dramatically (big amplitude values). While a small, quiet pool may move very little.