If “Fac” is 1.0 (the default), then the pixel is completely replaced with color_mid_ok otherwise it becomes the corresponding blend of this and its original value. But if both comparisons are greater, then the target pixel is adjusted from its initial value towards the color_mid_ok average, according to the “Fac” input socket value. If either comparison returns less than or equal, then the pixel is considered not to need correction. Also the difference between the components of color_mid (the average of all the neighbours) and those of the original target pixel are compared to the “Threshold”. The horizontal and vertical neighbours each have a weight of 1, while the diagonal neighbours are each given a lower weight of 1 2 ), to produce a fraction in the range, and the resulting fraction compared to the “Neighbor” input parameter. However, these neighbours are not treated equally: each one is given a weight that governs its relative importance to the computation. The target pixel being processed is compared with its eight neighbours. This is unlike blur filters, which average a bunch of pixels together, and can spread the firefly across a larger area instead of removing it.īut what do those “Threshold” and “Neighbor” parameters actually mean? The following explanation was put together from studying the Blender source code, mainly source/blender/compositor/operations/COM_DespeckleOperation.cpp. The despeckle filter is designed specifically to get rid of isolated anomalous pixels. I found if I reduced the “Threshold” filter parameter from its default 0.5 to something like 0.1, then all the fireflies did indeed disappear. By switching between these two, you should see that the default Despeckle filter settings have removed some of the fireflies, but not all. “RenderLayer” is the raw output from the renderer, while “Composite” is the result after going through the compositor. Next to the menu for selecting the image slot (which should be showing “Slot 1”), there is a menu for selecting which layer of the image to show. Make sure the image being shown is the “Render Result”. To see the effect of your changes, switch the 3D view window to an Image Editor window. So for our next fix, we will need to resort to the compositor.
After all, being settings that apply to the render as a whole, they can be something of a blunt instrument. And again, in our case, this option works: setting it to a value of, say, 1, does indeed fix the fireflies.īut, at some point, you may find that none of these three techniques will work for you: they may make no difference to the render, or may cause unacceptable loss of quality in places. This applies deliberate blurring to certain kinds of light bounces, sacrificing a bit of lighting accuracy for the sake of avoiding fireflies. The third renderer setting to try is the field just below the No Caustics checkbox, labelled “Filter Glossy”. In our simple case, checking this box does work.
However, the tooltip for this checkbox warns that the result can be a darker image. Caustics can be an important part of realistic lighting effects, but if your scene doesn’t need them, disabling them can help get rid of fireflies, and perhaps speed up the render as well. Set the Clamp back to 0, and this time look in the Light Paths panel, for the “No Caustics” checkbox. However, I have come across a case or two where this reduced the intensity of some bright indirect lighting, leading to a more subdued appearance for the overall render. In our simple example, this should be enough to fix the fireflies. Try changing the default 0 value to, say, 3, and rerender.
#Blender 3d animation fireflys full#
Normally 1.0 corresponds to full white, but some points can be brighter than this. If nonzero, this imposes a maximum value on the light-intensity calculations at each pixel. In the Sampling panel, look for the “Clamp” field. Look for the Sampling and Light Paths panels in the Render context, as at right. Probably the first things to try are one or two renderer settings. OK, now that we can create the problem, how do we solve it?