THE INVENTION RELATES TO A METHOD FOR ESTIMATING THE AMOUNT OF LIGHT SCATTERED BY A HETEROGENEOUS PARTICIPATING MEDIUM (2). IN ORDER TO OPTIMIZE RENDERING WHILE MINIMIZING THE REQUIRED CALCULATION TIMES, THE METHOD INCLUDES THE STEPS OF: SELECTING AT LEAST ONE SPACE SUBDIVISION LEVEL OF SAID MEDIUM (2) FROM A PLURALITY OF SPACE-SUBDIVISION HIERARCHICAL LEVELS BASED ON AT LEAST ONE PIECE OF ERROR INFORMATION REPRESENTATIVE OF A LIGHT ATTENUATION DIFFERENCE IN SAID MEDIUM IN AT LEAST ONE DIRECTION (120) BETWEEN TWO CONSECUTIVE HIERARCHICAL LEVELS ESTIMATING THE AMOUNT OF SCATTERED LIGHT BY MEANS OF SAMPLING SAID MEDIUM (2) ALONG AT LEAST ONE SCATTERING DIRECTION (120), THE SAMPLING BEING BASED ON AT LEAST ONE SELECTED SPACE-SUBDIVISION LEVEL.
