Optimal Modeling Techniques for Hitfilm

Hey gang,

So I'm working more with fully 3D modeled sets over the last week and I'm having an issue.  The set's floor is a giant plane, made up of two triangles to keep poly counts low.  It tends to "blink" out of existence a lot (it's oriented level with the floor plane at 0, 0, 0 in HF) depending on the camera view.  A lot of the time it'll be visible in the Composite viewer, and then when I look at the same shot on the Editor timeline it'll be gone.  I have to screw with the camera angles until it comes back into view, and it's keeping me from getting the shots I want.

This is weird.  The only thing I can think of is that since it's made up of such huge polys, HF's clipping algorithm is bugging out and assuming it's hidden.  Would I be able to solve this by dividing my floor planes into  greater number of faces?  Is there something else going on that I don't know about?


  • Chances are you've hit the nail on the head. Very large single polys can "blink" if they get to shallow angles relative to the camera. 

    At a basic level a poly is defined by four "points." Three vertices for corners and a "normal." The normal is at the center of the poly and has an orientation 90 degrees to the surface of the poly. Think of it like a pencil sticking straight up from the surface of a table. The normal is what is used to determine which way a poly is facing for rendering purposes, and, with a large poly, where the normal is far off-camera and, perhaps the corners are all off camera, the rendering engine may decide the poly isn't in view. Subdivision of your floor should fix the issue. 

  • shallow angles relative to the camera

    Now that I think about it, that's exactly when the issues were the worst.  We have a winner!

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