Hi! I need to know how I can make to run without problems the Natron app in GNU/Linux (Debian testing= sid/buster), the problem is the color rendered in a output video, it see inverted.
More likely than not one of two problems are happening. The first is that the alpha channel is not 1 and you are rendering to an non alpha based format so the alpha gets unpremultiplied at render time. Typical the solution to this problem is to put a shuffle node just before the write node and set the A to 1.
The second potential issue is that values in the graph, which operates in 32bit float, exceed the values of the output format, often 8bit. The will cause natron to try and squeeze, clamp, invert or some other oddity (depending on the node) when a value exceeds the output format’s total value range, but the viewer doesn’t reflect this. Putting a clamp node just before the write node, and connecting the viewer node to it will often cause the viewer to reflect the issue the write node will experience, if that is the issue; however, if what the viewer node produces is what one wants, then the only clamp point needed was at the end and the write node should render properly. if not then one will either have to trace back through their project and see where the offending issue is coming from and fix it, or output in a higher bit depth format.
The best solution is to use both these potential solutions in almost every project, even though they aren’t needed all the time.