I'm getting poor results with RSMB Vectors 3.x with overlapping 3D objects rendered in C4D R.11. The motion blur looks good where the objects border areas with no alpha, but I'm getting a sharp edge where the 3D objects overlap each other.
Until recently I'd been using the basic version of RSMB in conjunction with Lightwave. Lightwave can't output motion vectors, and RSMB was adequate for the most part. Since I've started learning and using C4D I'm interested in buying RSMB Vectors to create more accurate motion blur. But I'm not getting very good results in my tests. I followed the steps shown in this tutorial:
but in my tests overlapping objects, which should be blurred, exhibit a sharp edge, with the blur cropped by that edge. Here's an image that shows what's happening:
I'm still using the demo version of RSMB vectors.
In this render the sphere is rapidly moving left to right, and the blue plane is moving top to bottom; the silver plane is static. The right side of the sphere shows correct motion blur, but the left side that's overlapping other objects exhibits a sharp edge. The blur is set to 1 (default is .5) to better illustrate the problem. The blur on the left side of the sphere appears to be cropped within the shape its motion vector. Is it supposed to do that? The top edge of the blue plane is cropped too, though it's less obvious. That doesn't seem or look right. The basic version of RSMB properly blurs both sides of the sphere (though the blurs are kind of funky.)
If you have overlapping objects that move in different directions you need to have separate layers. It works best by layers.
here: either a new render without the background silver plate or you can actually since you have a vector pass just set as alpha in the motion vectors image something that does not have that element (just the two other objects).