fmri_show3d
===========

.. currentmodule:: fmri_toolbox

Description
-----------
FMRI_SHOW3D  3D isosurface rendering of brain activation.
Renders one or more activation datasets as coloured isosurfaces on a
transparent brain shell. Suitable for presenting whole-brain spatial
distributions of activations, networks, or ROIs.

Usage
-----
.. code-block:: matlab

    fmri_show3d(data)
    fmri_show3d(data, az, el, level, alphaval, color, maskalpha, crop)

Inputs
------
- **DATA**: fMRI data, vectorized (228453 x N) or volume (91x109x91xN). Each column N is rendered in a separate colour.
- **AZ**: Azimuth angle for view in degrees. Default: 40.
- **EL**: Elevation angle for view in degrees. Default: 15.
- **LEVEL**: Isosurface threshold (fraction of max). Default: 0.9.
- **ALPHAVAL**: Opacity of activation surface (0=transparent, 1=opaque). Default: 1.
- **COLOR**: (N x 3) RGB matrix: one colour per data column. Default: [1 0 0; 0 1 0; 0 0 1; 1 1 0; 1 0 1; 0 1 1].
- **MASKALPHA**: Opacity of the background brain shell. Default: 0.05.
- **CROP**: Bounding box [xmin xmax ymin ymax zmin zmax] to restrict rendering to a sub-volume. Default: full brain.

Examples
--------
.. code-block:: matlab

    fmri_show3d(activation_map)
    fmri_show3d(net1, 180, 10, 0.5, 0.8, [1 0 0], 0.1)
    fmri_show3d([net1 net2 net3], 40, 15, 0.9, 1, [1 0 0; 0 1 0; 0 0 1])

See Also
--------
- fmri_show3dba
- fmri_showcortex
- fmri_showslices
- fmri_braincake