unwanted seam in overlapping meshes

I am creating a plane, and a circle. I drag the circle over so it overlaps on to the plane. I make sure that the two objects are on the same Y coordinate. Then I join the meshes. When I render, orbiting around the object with the camera, I can see the outline where the meshes overlapped. I would expect it to be smooth. Any tips or recommended tutorials ?

If there is even the tiniest bit of difference in the y coordinate, you’ll see a seam at certain angles. Did you try selecting all the vertices and scaling along the y axis to zero? (s, y, 0) This got rid of the seam when I tried it.

I’d delete the verts that were overlapped and build new faces. You can set the pivot point in the center of the circle and rotate a circumference point to intersect the edge of the plane, to give you a nice join.

Great thanks. The scaling trick did not work, but the rotate did. I ended up with a dot in the render, the point around which the rotation occurred. I did a merge on all those center vertexes, and the dot went away.

Nice treasure chest BTW.