Hello!There are two basic types of animation. Animation of the flight, when the whole scene is static, and only the camera and dynamic animation are mobile, when there are moving objects in the scene. In English it is also called animation with moving objects.At you the second case, that is, animation with moving objects or dynamic animation.Flicker, also has its name, it is called flickering, from English flickering - flicker.Speaking of flicker, then there are no techniques for rendering the animation in V-Ray, because in the scene without GI flicker is actually not. Maximum, this is an inadequate quality of anti-aliasing, and there is nothing else, but an increase in Image sampler settings is not required.The same applies to the quality of shadows from light sources.When, say, the rendering of animation in V-ray, then in 99% of the cases it is a technique of rendering it is Global illumination component. On this, technically correct, it will not talk about rendering the animation in Vray, but about rendering GI in V-Ray.There are three techniques for rendering GI for dynamic animation in V-Ray.The first, the most banal. No Irradiance Map and Light Cache. Pure Brute force GI. Both the "primary" and the "secondary".Long, noisy, but no flicker.The second is to say classical. IM + LC. In it, the main thing is rendering IM. The fact is that the flicker is due to a rather arbitrary pattern of the arrangement of IM samples across the stage. In the end, rendering the first frame, IM looks in one way, rendering the second frame, already different and, as a consequence, noise and artifacts of GI, from frame to frame, look and are arranged differently. Actually this is a flicker.In order to somehow average the Irradiance Map artifacts, on different frames, first render the Irradiance maps for each frame, and then, during rendering, slash them into one Irradiance card. Thus, the current frame, rendered using the Irradiance Map, from the previous, its and next frames, thus their artifacts are averaged (blurred) and flicker is almost completely minimized.For this, there's nothing to change, go to Irradiance Map settings and in the Mode section, set the parameter with the same name in the Animation (prepass) mode. You specify the folder where frame-by-frame saving of Irradiance maps will be conducted and you start the render.Then, when all the maps for each frame of the animation are calculated, go there, but you already select the option Animation (rendering), indicating where the Irradiance maps are calculated and render.It is very tedious to configure, but quickly and without artifacts. The noise from GI is also minimal.The third, so to speak, a modified version of the previous technology. In it, rendering IM is exactly the same as in the previous method, but a special rendering mode LC is added. This method is that in the Light cache the tick box Use camera path is activated. Then V-ray, at once, calculates LC samples, for fixed objects, and uses them throughout the animation, of course, sampling of moving objects is carried out in a frame-by-frame manner. Thus, the flickering from the LC on fixed objects of the scene is reduced, thereby reducing the overall "contribution" to the flicker of GI.Also, as in the previous case, it is tedious to configure, but to render quickly and with even less noticeable flickering.
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As I already said, Screw antialiasing and put Brute force GI. If the flicker disappears, then, the matter is in the settings. It is not necessary to render the whole animation. Try a couple of seconds to count and see.
After that, the series need to abandon high antialiasing settings and slazit with Brute force. Until then, until a new appear old artifacts. So, by process of elimination, you will find the culprit of the problem.
By the way, we do not advise on static and do not recommend to apply the animation the Use light cache for glossy rays's . I can personally attest to that Use light cache for glossy rays flicker on moving objects, especially in the refraction.