Author Topic: Lighting confusion  (Read 6021 times)

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Offline ilovedividends

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Lighting confusion
« on: November 14, 2014, 04:55:00 pm »
I am a bit confused on how lighting works in Keyshot.  When I load a studio lighting it appears sometimes there are lights below my model when my model is resting on the ground as I open it up.  Is this correct or am I seeing a reflection of this light from above?

For instance when I load the 'Light Tent Screen Top 2K'  I see a light coming from below the ground plane.

Also, what does 2K mean?

thomasteger

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Re: Lighting confusion
« Reply #1 on: November 16, 2014, 04:26:14 am »
An HDRI is applied to a spherical environment. Zoom out until you see the sphere. This way you see how the HDRI is applied to the sphere. You can control the placement of the HDRI by adjusting the height parameter in the environment tab (up/down).

2k refers to the resolution, in this case 2,000 by 1,000 pixels.

Offline ilovedividends

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Re: Lighting confusion
« Reply #2 on: November 17, 2014, 12:38:25 am »
What is confusing me is the attached pictures.  In each picture it appears in this environment that the lighting is coming from below as well as above.  This object is resting on the ground so that is what is confusing me.

Appreciate the help btw, what a learning curve  :o

Offline MealeaYing

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Re: Lighting confusion
« Reply #3 on: June 17, 2016, 12:02:09 pm »
If I am correct what you are seeing is actually because you haven't got a "floor" yet.
KeyShot is an environment inside a sphere, when you import an object into it, it's hovering roughly in the middle of that sphere and unless you make one, there is no floor. The funny thing is that even though it's not there you can cast shadows and reflections on it.
The sphere has an HDRI mapped onto the inside of it, with no floor that HDRI is visible to your entire object, and since the HDRI is making the light, it's getting all over your stuff and screwing you up.
Try this:
Import your object and in the Edit Menu, under Add Geometry select Ground Plane.
This will give you a floor and, in theory, prevent your lighting from coming from everywhere inside the sphere (unless you make the ground plane reflective!).

I hope that helps.

Cheers,
Mealea

guest84672

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Re: Lighting confusion
« Reply #4 on: June 17, 2016, 02:33:22 pm »
That is not really correct. There is always a floor that catches the shadow, and reflections if turned on. The floor, or better ground plane is transparent, so you can see through, and also light will shine through from underneath.

We have a feature that allows you to flatten the ground. This will "squish' the sphere from the bottom.

A physical ground plane with the ground plane material has the same effect, yet gives you the ability to control reflectivity, roughness, and bumpiness. You can also change the material to any other material that KeyShot offers. Based on the material you choose, the ground plane may no longer be transparent.

Zoom all the way out and see how the scene is set up - spherical environment, ground plane in the middle.

I hope this helps.

Offline MealeaYing

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Re: Lighting confusion
« Reply #5 on: June 18, 2016, 08:47:31 am »
Oh wow....
THAT is a strange and cool feature, I had no idea!
Thanks!