1.0.1
* added camera tone mapping
* added regular_tabulated spectrum type.
Camera tone mapping is an attempt to model the image generation process of a digital camera, and shares some parameters with a real camera.
ev_adjust is exposure-value adjustment; increasing this value by 1 will effectively double the 'sensor output'.
film speed (film ISO) has much the same effect, except it's a linear factor. Doubling the film ISO will double the 'sensor output'.
The response function uses data from
http://www1.cs.columbia.edu/CAVE/softwa ... b/dorf.php
, as such many cameras should be able to be modelled.
There is a calibration constant in the code that relates incident energy density on the sensor to the value input to the response function; this constant was determined thanks to some test images from Carbon.
I still need some more test scenes to make sure the whole camera tone mapping model is correct however.
How to use camera tone mapping:
Code: Select all
<tonemapping>
<camera>
<ev_adjust>0.0</ev_adjust>
<film_iso>100.0</film_iso>
<response_function_path>data/camera_response_functions/dscs315.txt</response_function_path>
</camera>
</tonemapping>
The regular_tabulated spectrum type allows (nearly) arbitrary spectra to be defined in the scene file.
How to use regular tabulated spectrum type:
Code: Select all
<material>
<name>mat1</name>
<diffuse>
<albedo_spectrum>
<regular_tabulated>
<start_wavelength>0.4E-06</start_wavelength>
<end_wavelength>0.7E-06</end_wavelength>
<num_values>10</num_values>
<values>
1 0.9 0.5 0.345 0 0 0 0 0 0
</values>
</regular_tabulated>
</albedo_spectrum>
</diffuse>
</material>
