Mode – Selects the mode of the irradiance map: New map – When this option is selected, a new photon map is generated. It overwrites any previous photon maps left over from previous rendering. Save to file – Saves an already generated photon map to a file. From file – When enabled V-Ray does not compute the photon map but loads it from a file. Press the Browse button on the right to specify the file name and path. Multiplier – A multiplier for the caustics strength. It is global and applies to all light sources that generate caustics. If you want different multipliers for the different light sources, then you should use the local light settings. Note: This multiplier is cumulative with the multipliers in the local light settings. Search distance – When V-Ray needs to render the caustics effect at a given surface point, it searches for a number photons on that surface in the area surrounding the shaded point (search area). The search area in fact is a circle with center the original photon and its radius is equal to the Search distance value. Smaller values produce sharper, but perhaps more noisy caustics; larger values produce smoother, but blurrier caustics. For more information, see The Search Distance Parameter example below. Max photons – Specifies the maximum number of photons that are considered when rendering the caustics effect on a surface. Smaller values cause fewer photons to be used and the caustics are sharper, but noisier. Larger values produce smoother, but blurrier caustics. The special value of 0 means that V-Ray uses all the photons that it can find inside the search area. For more information, see The Max Photons example below. Max density – Limits the resolution (and thus the memory) of the caustics photon map. Whenever V-Ray needs to store a new photon in the caustics photon map, it first checks if there are any other photons within a distance specified by Max density. If there is already a suitable photon in the map, V-Ray adds the energy of the new photon to the one in the map. Otherwise, V-Ray stores the new photon in the photon map. Using this options allows you to shoot many photons (and thus get smoother results), while keeping the size of the caustics photon map manageable. File – The file name with the caustics photon map to be loaded when the Mode is set to From file. Auto save - When this is turned on, V-Ray automatically saves the caustics photon map to the provided file and location upon finishing the render. |