XML File Format

This documents the file format used by the standard implementation to specify individual images and animations. The XML meta-format is used to facilitate predictable parsing and compatibility. No formal DTD is available, but the important part is the semantics of the recognized elements and attributes, and those are given here.

The basic template is:

<flame> <xform/> <xform/> ... <color/> <color/> ... </flame>

The attributes of the flame element are:

Name	Type	Description
		//General Attributes//
time	float	Time (frame number) when these parameters are realized.
name	string	name of flame
url	string	Website of designer
nick	string	Name or nickname of designer
interpolation	string	how flames change over time. "smooth" enables catmull-rom interpolation, "linear" for piecewise straight lines, see Interpolation .
palette_interpolation	string	"hsv_circular" (default), "hsv", "rgb", or "sweep" methods of interpolating between colormaps, see Palette Interpolation
hsv_rgb_palette_blend	float	0.0 (default) means regular palette interpolation in hsv_circular space, blending to 1.0 meaning interpolation in rgb space.
palette_mode	string	"step" (default) or "linear". how to interpolate between entries in the palette.
interpolation_type	string	method for Interpolation xform positions: options are "log","linear","old"
		//Camera Attributes//
size	int int	The width and height in pixels of the output image.
center	float float	The coordinates of the center of the output image
scale	float	The number of pixels per unit in the image plane.
rotate	float	Global camera rotation angle of the image plane.
zoom	float	Scale the image (the camera, not the number of pixels) by this power of two. Also scales the quality to compensate. Together the size, center, scale, and zoom attributes specify the camera that maps the image plane to output image.
		//Temporal and Spatial Filter Attributes//
filter_shape	string	Shape of redux filter to use. Defaults to "gaussian" but other options are hermite, box, triangle, bspline, mitchell, blackman, hanning, hamming, quadratic. See Image Reduction Kernels.
filter	non-negative float	The multiplier on the size of the kernel for the filter used to resize the oversampled image down to the output image.
temporal_filter_type	string	Kernel used to describe the relative importance of certain time steps within a motion blur. "box" (default), "exp" or "gaussian"
temporal_filter_width	float	length of motion blur in units of frames
temporal_filter_exp	float	exponent controlling direction and rate of motion blur for "exp" mode temporal filter type.
		//Color Attributes//
background	float float float	The color of the background as an RGB triple with each component in [0, 1].
brightness	positive float	Linear scale on luminance.
gamma	positive float	The inverse exponent. Values larger than one brighten the dark parts of the image. Usually between 2 and 4.
vibrancy	float	Blend between applying gamma to each channel independently (zero) for pastel and ghostly white images, and applying gamma from the alpha channel to each channel (one) for saturated colors.
palette	int	One of 701 standard color-maps that are delivered with flam3.
hue	float	Added to the hue component of the colors from the palette. 0.5 means to rotate 180 degrees in color space.
gamma_threshold	float default=0.01	Linearization threshold, see Gamma Threshold
		//Rendering Attributes//
quality	positive float	The number of samples per pixel on average.
supersample	positive integer	The degree of spatial oversampling on both axes. Memory use is quadratic in this parameter. Typically less than 4.
oversample	positive integer	Deprecated, old name for supersample. Do not use.
temporal_samples	integer	The number of time samples used for motion blur.
passes	positive integer	The number of temporal sub-samples, though also useful for preventing clamping even when not doing animation. Larger values reduce the resolution of the logarithm. Unless you understand this feature very clearly, you should probably be using temporal_samples.
		//Density Estimation//
estimator_radius	integer default=9	MaxKernelRadius, 0=disabled
estimator_minimum	integer default=0	MinKernelRadius
estimator_curve	float default=0.4	Alpha

Xform, symmetry, and color elements may appear inside the flame element. An xform element specifies a function in the function system, and a symmetry element specifies a collection of functions as described above. Color elements provide finer control over the colors than the palette attribute.

Name	Type	Description
weight	non-negative float	The relative probability that this function will be chosen by the chaos game.
color	float	The color index associated with this function, normally in [0,1].
symmetry	float	<= 0 means this xform animates, also controls color influence.
coefs	6 floats	The coefficients for the affine part of the function, in row order (a d b e c f).
post	6 floats	The coefficients for the affine part of the post function, in row order (a d b e c f).
var	up to 14 floats	Deprecated: The variational coefficients //vi j// for this function //i//. Any coefficients not given are assumed to be zero.
var1	integer	Deprecated: Shorthand for a var attribute with all coefficients zero except the one specified is one. So var1="2" is equivalent to var="0 0 1 0 0 ..." and var1="0" to var="1 0 0 ...".

In addition, each of the variations names may appear as an element of an xform. Its value is a float that is the variational coefficient. For example:

<xform weight="0.103" color="0" symmetry="0" julia="0.6" coefs="0.531292 -0.369204 0.189104 0.990545 -1.55337 -0.507086"/>

and

<xform weight="0.132" color="0.1" symmetry="0" linear="0.13" spherical="0.03" heart="0.07" disc="1" julia="1" coefs="-0.02833 0.14165 -1.21818 -0.509937 0.790042 -1.38261"/>

The symmetry element has one attribute kind with a non-zero integer value that is the degree of rotational symmetry. A negative value means a dihedral symmetry. Kind one means no symmetry.

The color element has two attributes: index and rgb. The index value is an integer in [0,255] and the rgb value is three integers in [0,255]. It sets a single entry of the color map, so you need 256 of them. You cannot specify both a palette attribute and color elements.

For example:

<flame ...>
  <color index="0" rgb="20 12 123"/>
  <color index="1" rgb="21 13 130"/>
  ...
  <color index="255" rgb="200 42 0"/> 
<flame/>

Flames can also have edit histories that record their family lineage and any other changes to the genome, like this:

<edit date="Fri Jul 18 19:21:37 EDT 2008" id="888" action="clone brood">
  <edit date="Tue Jul 15 04:12:39 EDT 2008" id="766" action="cross alternate 1: 0 0 1 1 cmap_cross 0: 34 137 156 174 improved colors" filename="upload" index="0">
    <edit date="Tue Jul 1 11:07:02 EDT 2008" nick="m2" url="www.myspace.com/mthatsalowercasem2" id="304" action="clone upload" filename="spex" index="0">
      <edit filename="upload" index="0"/>
    </edit>
    <edit date="Wed Jun 25 00:21:20 EDT 2008" id="104" action="clone brood" filename="spex" index="0">
      <edit date="Tue Jun 24 02:42:36 EDT 2008" id="82" action="cross alternate 1: 1 0 0 1 cmap_cross 0: 7 74 179 221" filename="upload" index="0">
      <edit date="Sun Mar 26 15:48:04 PST 2006" action="genebank 198 20903" filename="genebank.flam3" index="579"/>
      <edit date="Sun Mar 26 15:46:19 PST 2006" action="genebank 191 16594" filename="genebank.flam3" index="181"/> 
    </edit>
  </edit>
</edit>
</edit>