Hi everyone,
I’m new to krakatoa, I’m getting very nice render output in 600*400 with 1 million particles, I want same output in 2k but it’s coming very very low density.So, How to control Particle Size?
How control Self particle shadow color?
Krakatoa is pixel scale rendering or World scale rendering?
With Regards,
Murali
Hi,
Krakatoa 1.1.x was a pure point renderer, each particle could not be larger than a pixel. Obviously, the apparent density was dependent on the pixel coverage and image resolution, so increasing the resolution would call for increasing the particle count to get the right coverage (short of rescaling the low-res image which would probably not look that good). In general, if you want to smooth quality of point rendering, your only option is creating more partitions of the same particle system to fill the volume. This mode is still available in the latest 1.5.x version.
Krakatoa 1.5.x added a voxel rendering mode where particles are registered on a world-space-sized grid. Thus, the size of the smallest particle would be the size of a single voxel. Using the Filter Radius property, the voxel can also be smoothed using the neighbor voxels, producing larger smoother particles instead of obvious “cubes”. If the voxel size is selected very small, close to pixel size, the results would look quite similar to particle (point) rendering (but would render slower). Increasing the output image resolution would not necessarily require an increase of particle count, but a single voxel would be represented by more pixels and in general quality would suffer, too. We use voxel rendering for things like thick clouds of smoke, fumeFX rendering etc. where smoothness is more important than fine detail.
You can see some comparisons of the two approaches here:
software.primefocusworld.com/sof … g_mode.php
and here
software.primefocusworld.com/sof … _Rendering
As for the shadow color, in v1.1.x it was always gray without any way to control it. (Light Absorption was performed uniformly for R,G and B).
As of v1.5.0, you get a new Absorption channel to control how the R, G and B are attenuated (including the ability to use the Filer Map in a Standard Material, the Absorption map in a Krakatoa Material, an Absorption color and/or map in the Global Overrides or a per-particle Absorption value using the MagmaFlow channel editor), so there is nearly no limit to what you can do.
See here:
software.primefocusworld.com/sof … on_Channel
There are also ways that you can increase apparent spatial density without increasing the number of particles by rendering in passes and averaging the results, or by filtering the output image.
For instance, you can apply position noise to a particle system to increase the sampling in screen space without increasing the sampling in world space. Likewise, you can resize a small render to a larger image or apply even something as simple as rank filtering to fill in missing samples in screen space.