Author Topic: Reflecting objects question  (Read 4763 times)

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Offline carterhickmandesigns

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Reflecting objects question
« on: April 14, 2016, 01:36:13 pm »
Is it possible to have a mesh item be visible to reflections but not visible to the camera?  See the attached image.  I would like the plane with the grid pattern to be visible to reflections but not to the final image.  Did that make sense?  Basically reflection cards that are not visible to the final render.

Offline bdesign

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Re: Reflecting objects question
« Reply #1 on: April 14, 2016, 01:43:46 pm »
Hey-
Check out this thread. I provide a technique for achieving this. Hope it is helpful.

Eric

https://www.keyshot.com/forum/index.php?topic=12277.0

Offline carterhickmandesigns

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Re: Reflecting objects question
« Reply #2 on: April 14, 2016, 02:21:41 pm »
hmm I cannot find the backface utility node?

Offline bdesign

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Re: Reflecting objects question
« Reply #3 on: April 14, 2016, 02:33:27 pm »
You have to enable Experimental Features under Edit>Preferences>Advanced. You may need to restart KeyShot afterwards. Then, right-click in the material graph; under Utilities, you should see Surface Backside Mask.

Eric

Offline Speedster

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Re: Reflecting objects question
« Reply #4 on: April 14, 2016, 04:43:09 pm »
The other option is to pull a clown pass, use it for selection and erase (delete) the panel in post.
Bill G

Offline carterhickmandesigns

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Re: Reflecting objects question
« Reply #5 on: April 14, 2016, 04:47:54 pm »
Bill, I think that would then create a shadow and block the lighting from the HDR.  No sure not infront of a Keyshot instance right now.  Will test it in the morning.

Carter

Offline carterhickmandesigns

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Re: Reflecting objects question
« Reply #6 on: April 15, 2016, 08:34:57 am »
Got it!  So what I did was really very simple.  I used an Emissive material and then attached an image to the Color input.   I use the UV on the plane to position the image.  I then just deselected the "Visible to Camera" in the Advanced options of the Emissive shader.  Works like a champ.

No if we could just get the  same to work with the Camera projection and not UV we would be set!

Carter

Offline carterhickmandesigns

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Re: Reflecting objects question
« Reply #7 on: April 15, 2016, 08:38:56 am »
Still not perfect as I wish.  I would like for the hdr lighting to still come thu the plane.  So basically it would be the reflection coming thru

Offline TpwUK

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Re: Reflecting objects question
« Reply #8 on: April 15, 2016, 09:19:55 am »
Still not perfect as I wish.  I would like for the hdr lighting to still come thu the plane.  So basically it would be the reflection coming thru

Do you want something like this ?

If so then use the HDRi editor and add an image pin. The reflection in my sphere is using the second image as a pin light and can be adjusted in size, fall off, rotation etc etc.


Martin

Offline carterhickmandesigns

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Re: Reflecting objects question
« Reply #9 on: April 15, 2016, 09:39:38 am »
yes I had tried that before as well and that was my first plan of attack but did not have the results I was looking for.