Fisheye camera

Description

../../../_images/fisheyecam.jpg

Cornell box rendered with a fisheye camera (Equisolid projection)

Instrument This instrument is a camera with a circular fisheye lens, representing a 180° field of view over a circular image.

The following fisheye projections are available:

  • Equisolid : \(2*f*sin(\theta/2)\)
  • Equidistant : \(f*\theta\)
  • Stereographic : \(2*f*tan(\theta/2)\)
  • Orthographic : \(f*sin(\theta)\)

The focal length of the lens is automatically calculated to fit the width of the circular image inside the rectangular buffer.

Children Nodes

This node may have a variable number of output children with custom names.

Sensor sensor List of channels defined by a sensitivity spectrum
Output user-defined First output preset
Output user-defined Second output preset
Output user-defined …

Parameters

name type description
xresolution integer Horizontal buffer resolution
yresolution integer Vertical buffer resolution
shutter real Shutter time or exposure, in seconds
wlmin real Low bound of simulation wavelength range
wlmax real High bound of simulation wavelength range
projection list The fisheye prohjection, can be equisolid, equidistant, stereographic or orthographic
pixelfilter list The ray pixel filter
pos vec3 The camera position : center of pupils apertures, as well as principal points
forwards vec3 The camera optical axis, or view direction. Should be orthogonal to up
up vec3 The camera up axis. Should be orthogonal to forwards
focusdistance real The lens focusing distance in meters. Set to zero for infinite focus distance
autofocus boolean Set to true for setting the focus distance to the first geometry met in the forward direction
fnumber real The lens aperture F-number
sensor_ar real The sensor aspect ratio. Physical width/height ratio of the recorded image, but not necessarily equal to pixel aspect ratio (xresolution/yresolution. Must be greater than 0
sensor_width real The sensor width in meters, such as 0.036 for 35mm film cameras. Must be greater than 0

Ocean XML 5.0 example

<instrument type="fisheyecam" name="fisheye">
     <prm xresolution="512"/>
     <prm yresolution="512"/>
     <prm shutter="0.8"/>
     <prm wlmin="3.8e-007"/>
     <prm wlmax="7.8e-007"/>
     <prm pixelfilter="bilinear"/>
     <prm projection="equisolid"/>
     <prm pos="0.278 0.273   0"/>
     <prm forwards="0        0       1"/>
     <prm up="0      1       0"/>
     <prm focusdistance="2"/>
     <prm autofocus="true"/>
     <prm fnumber="5.6"/>
     <prm sensor_ar="1"/>
     <prm sensor_width="0.025"/>
     <sensor type="ciexyz" name="sensor" y_only="false"/>
     <output type="rgbimage" name="image">
             <prm colorspace="srgb"/>
             <prm depth="8"/>
             <prm xwhite="0.31271"/>
             <prm ywhite="0.32902"/>
             <prm hcc="0.32"/>
             <prm drawinfo="false"/>
             <filter type="gain" name="filter1" enabled="true" gainev="0"/>
             <filter type="reinhardglobal" name="filter2" enabled="true" stops="1" strength="0.8"/>
     </output>
</instrument>