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Surface emitters for display rendering

PostPosted: Thu Sep 11, 2014 8:48 am
by Veronique
Hi all,

My aim is to simulate a display in a given environment.
From start, my obj is a simple rectangle with the top surface designed as Diffuse material with an Emission designed as texture Emission . Emission distribution is set to greyscale and an .ies file corresponding to a display emission (for example emission limited to 20° for narrow angular display).
My wish was to superpose 3 such displays (one for each R,G,B canal with different .ies file for each one) so as to simulate for any color....and even further to use the "efficiency of texture" set to greyscale image to simulate for any image on a display.

The result is not the one expected especially because (I think) I don't correctly manage the "UVTransform" , "projection" and "projection- coordinate space" parameters of the Emission/Texture Emission node..but I can't find details on them .
Can anyone help me settle correctly those parameters for the above purpose.
Thanks a lot for any help.

Re: Surface emitters for display rendering

PostPosted: Fri Sep 12, 2014 12:48 am
by FooZe
Hi Veronique,

Have you see the information here: ... age_id=901 ?

Does that help?


Re: Surface emitters for display rendering

PostPosted: Fri Sep 12, 2014 9:08 am
by Veronique
Hi Chris,

Thanks for your post.
Indeed I can understand Projection and UVTransform When dealing with the image displayed on the simulated screen. If I want for example display three horizontal (R,G,B) bands along the simulated screen, I choose an image with the three horizontal bands (set into Efficiency of Texture/RGBImage) , choose Mesh UV projection, choose UVTransform as 2D transformation and adjust UVTransform parameters (rotation, scale and translation) to correctly see the tree bands on my simulated screen surface.
The ones I don't understand are the projection and UVTransform from the distribution node.
I choose an IES file specially created so that light is emitted horizontally into small pencils every 10° of incidence (see distribution attached). I would like that every point on the surface has the same angular distribution (=the one defined in the IES file). From that I should see vertical bands (RGBimage/black/RGBimage/black) : image is displayed when angular position from the eye to the point on the display lays into the pencils of light.
I tried an other IES file where light is emitted only in a small cone of 20°. Image should be all visible while looking at the display on axis and should quickly disappear while roating the display.
I tried the same parameters MeshUV and 2D transformation, but the changes in the parameters (scale, rotation) do so strange behavior....
What parameters to set for projection en UVtransform IN THE DISTRIBUTION NODE so ensure every point is simulated with the same IES distribution?
Sorry for that so long post and Thanks for any further help.