View Full Version : Mia_Exposure_Photographic - Simple Question

11 November 2009, 05:16 PM
Okay, so I've setup my sun and sky, then deleted the mia_exposure_simple and replaced it with a mia_exposure_photographic. My render looks fantastic, but theres a slight problem. Even the image plane thats connected to the camera is effected by the lense shader. Now, its quite difficult to colour match the geometry to the image plane.

Is there anyway that I can have the lense shader only effect the 3D geometry, but not my image plane, instead of flipping to another frame buffer which already has the background image loaded ?

Thanks in advance.

- K

11 November 2009, 06:50 AM
It is annoying and you can't actually tell the lens shader (or image plane) to ignore it, but you can set the image plane to 'texture' mode instead of 'image file', and that way you can use the gammaCorrect node as you would with your textures to de-gamma the image plane. Of course.. that means the image plane will look wrong in your viewports. A way around *that* is to use the 'pre render MEL' and 'post render MEL' features in the Render Settings to change the gammaCorrect's values for you.

As in 'pre render MEL' sets the gammaCorrect to 0.454 and then the 'post render MEL' sets it back to 1.0.


12 December 2009, 08:35 PM
Hi Jozvex,

Long time no see, and thanks for the reply.

I did try the file -> gamma -> image plane, but it didn't seem to work as I think the shader does more than just change the gamma. The iso, shutter speed, cm2 sturation all play a part in the final outcome of the image.

Oh well, back to the drawing board.


12 December 2009, 08:44 PM
the way i got around this problem was to put the image plane on its own render layer, with no lens shader applied on that layer. put this layer underneath your beauty layer in the stacking order. then under the render layer options, choose "render all layers" so that your tonemapped image is composited on top of your original image plane with the colors intact.

12 December 2009, 09:44 PM
Thanks for the tip.

Will give it a try.

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