Which light type would you suggest for speed, efficiency and general predictability with Krakatoa?
I’m guessing you’re going to say spotlights over point lights, but how about area lights? We can specify Z-Direction in C4D so the light emission is directional. I mostly prefer the look from an area light over a spotlight with normal rendering and was wondering how this might influence krakatoa renders.
Also regarding shadows, is it best to stick with shadow maps, does Krakatoa read the shadow map size from the light? How does Krakatoa deal with area shadows?
Krakatoa does NOT use the lights of C4D as such, it only reads some parameters from them and uses its internal lights. The only light types supported internally are Spot, Point and Directional. No Area Lights. Additionally, when rendering Voxels, Point lights are also not supported, so you are left with only Spots and Directs. This is a limitation due to the way the current version of Krakatoa calculates volumetric lighting and attenuation. So while an Area light might appear to work with KC4D, it is rendered as a different type internally.
Furthermore, Krakatoa Direct lights are not infinite, they have a source and a cylindrical area where shadows are calculated (in other words, they are kinda like Parallel Spots).
So yeah, I would recommend Spots for best control over where the shadows are calculated. Point lights have to calculate a cubic map with 6 maps for each side, and the quality where the maps meet at the edges and corners of the box can be lower than in the centers of the maps.
It does not matter, Krakatoa reads the Shadow Map size even if the light is NOT set to use Shadow Map. Krakatoa ALWAYS calculates light attenuation (volumetric shadow casting), but it does not use Shadow Maps as you know them, but square Attenuation Maps in the resolution specified by the Shadow Map settings of the light. In general, Krakatoa would default to 512x512 size, but in C4D it always seems to find a valid parameter in the C4D lights, so it uses whatever the Shadow Maps resolution is set to. There is no alternative attenuation calculation method, so there is nothing you can change. Note that if Shadow casting is set to None for a light, Meshes tagged as “Visible To Lights” using the Mesh tag will not cast shadows on particles. ANY shadow type (Shadow Maps, Raytraced or Area) will produce the shadow casting from the mesh into the particles.
We have tried to take into account all Krakatoa and C4D light properties available and matched them as well as possible, but they are NOT the same lights and a lot of C4D properties are just ignored, and some like aspect work slightly differently. If you want to control the “native Krakatoa lights”, you can drop a Light tag on a C4D light and override the properties. In that case, the type of the light will control which of the several light type tabs will come into play…