How do you place a plane directly in front of the camera?

RexRed

How do you place a plane directly in front of the camera?

This is a weird question, but I thought I would ask it. Someone smarter than me can figure it out.

I want a plane to exactly fit without being even a tiny fraction off in front of my camera.

When I zero the camera then I parent a plane to it and rotate the plane 90 degrees on the X axis the plane ends up behind the lens of the camera.

When I put the plane into the scene it seems the plane has every measurement, but pixels and one can only make a square plane. The plane must be adjusted after it is created. And the surface of the plane does not accurately account for the camera's depth distortions.  

You increase and decrease the size of the plane by percentage points on the x and y parameters not in pixels. And when you move the plane ahead -z to be in front of the lens it is by a numerical value but that value is not stated and the numerical value of the actual distance of the camera lens' distance from zero is not precisely given.

For my purpose the plane must fit precisely in the camera's field of vision.

And then there is field of vision, what is the camera’s dept of field and is the camera's vision somehow distorted?

If I were to render a depth map it would not align with the camera’s point of view and the math and geometry to do this seems too abstract and complex for my mind to figure out.

This becomes vital if the image on the plane were to be a transparency of the scene. The distortions and inaccuracy of math becomes readily visible in the overlay.

The surface on the plane must have exact congruence with the camera lens.

Layering a depth map transparency can easily be done post work in Photoshop but I have alwasy wondered if it could be done pre-render.

lukon100

I find this question very confusing. I can't tell what you really want to do. Instinctively, it appears you want to put a plane exaclty at the internal focal point of the camera, exactly at the point where all the virtual light rays converge and pass on inverted before they go on to hit the virtual film surface. But on the other hand, you keep saying you want the plane to be in front of the camera - in front of the camera, yet at zero distance from the camera. Way confusing to me. I'm having trouble undertanding what exaclty you mean by the camera as a 3D object, and likewise what you mean by "in front of it yet zero distance in front of it".

Perhaps I could understand your terminology about the camera if I could understand your goal. I see that you implicitly drscribe your goal in terms of things like "layering a depth map transparency" and so on. Unfortunately, I don't know what such things are. I'm an amature.

But, I did some experimenting in positioning a plane at a camera. And perhaps what I learned in my experimenting could help you.

I created a camera.

Then I created a 1m plane with Z+ orientation.

Then I parented the plane to the camera.

Then I set all the translations and rotation values of the plane to zero.

At this pont the plane was invisible to the camera.

Then I moved the plane forward by going -Z until the plane appeared in the camera. The plane appeared at exacly any -Z value beyond -5.00, such as -5.00001. And at exacly -5.00, the plane would intermittantly flash in and out of visibility when I moved the camera in any way. All this remained true regardless of frame width or focal distance and some other settings like that.

So, -5 Z may be a position within the camera object of some interest to you.