I’m quite new to the compositor so maybe my question is naive but please bear with me XD
Okay so I am doing some tests, I want a chair to be set on the floor of a picture, and on the floor, just under the chair, I want a wireframe render of the supposed ground to imply that the chair is intersecting with the floor.
Basically, I made a model of the floor on which I have rendered a free style, and I have put a circular plane on the spot I want the freestyle to be visible so I could use it as a mask.
On my first try it almost worked, but the problem was I didn’t like how it looked because the wireframe went over the chair, yet I wanted the other way around.
So I have done this:
Here’s how I reasoned through this: I have my three render layers, that is to say the chair, the free style and the intersection. I started by treating the intersection: I took the alpha and blurred it so it gave me a black and white mask through with the free style would appear and disappear smoothly in a circle beneath the chair.
Then I took my free style render layer, and with the set alpha, I told it that now its alpha was the one I had just designed with the blur below. Then I combined it with the chair with an alpha over, and the result was what I wanted:
So until this point, no particular problem. I then decide to combine this image to the background image… And here it gives me this:
I have absolutely no idea how it can possibly give me this when I changed the alpha of the freestyle so that it shows up only under the armchair. I even tried to save the view of the freestyle through the mask as an image and combine that image, I still get the same result…
Can you help me please?