Fbm

Detailed Description

Functions
void	InitFbm (Float *table, Int32 max_octaves, Float lacunarity, Float h)
Float	Fbm (Float *table, const Vector &p, Float oct)
Float	Fbm (Float *table, const Vector &p, Float t, Float oct)
Float	RidgedMultifractal (Float *table, const Vector &p, Float oct, Float offset, Float gain)

Function Documentation

InitFbm()

void cinema::InitFbm	(	Float *	table,
		Int32	max_octaves,
		Float	lacunarity,
		Float	h
	)

Initializes the tables needed for the Fractional Brownian Motion.
Example:

Float arr[20];
InitFbm(arr, 10, 2.0, 0.5); // max_octaves must not exceed 18 (as the array can contain 20 values maximum)

Parameters

[in]	table	A preallocated array of size max_octaves+2. The caller owns the pointed array.
[in]	max_octaves	The number of octaves for the table.
[in]	lacunarity	The gap between successive frequencies.
[in]	h	The fractal increment parameter.

Fbm() [1/2]

Float cinema::Fbm	(	Float *	table,
		const Vector &	p,
		Float	oct
	)

Generates a Fractional Brownian Motion value.

Note

InitFbm() must be called before this function.

Parameters

[in]	table	The preallocated and initialized table by InitFbm(). The caller owns the pointed array.
[in]	p	The evaluation point.
[in]	oct	The number of octaves. Must not exceed the max_octaves value passed to InitFbm(), but can be lower.

Returns

The fBm value.

Fbm() [2/2]

Float cinema::Fbm	(	Float *	table,
		const Vector &	p,
		Float	t,
		Float	oct
	)

Generates a Fractional Brownian Motion value.

Note

InitFbm() must be called before this function.

Parameters

[in]	table	The preallocated and initialized table by InitFbm(). The caller owns the pointed array.
[in]	p	The evaluation point.
[in]	t	The time.
[in]	oct	The number of octaves. Must not exceed the max_octaves value passed to InitFbm(), but can be lower.

Returns

The fBm value.

RidgedMultifractal()

Float cinema::RidgedMultifractal	(	Float *	table,
		const Vector &	p,
		Float	oct,
		Float	offset,
		Float	gain
	)

Generates a fractal function used for such things as landscapes or mountain ranges.

Note

InitFbm() must be called before this function.

Parameters

[in]	table	The preallocated and initialized table by InitFbm(). The caller owns the pointed array.
[in]	p	The evaluation point.
[in]	oct	The number of octaves. Must not exceed the max_octaves value passed to InitFbm(), but can be lower.
[in]	offset	The zero offset, this controls the multi-fractal.
[in]	gain	The amplification of the fractal value.

Returns

The fractal value.