KeyShot Forum

Technical discussions => Lighting => Topic started by: zooropa on February 16, 2018, 02:12:42 AM

Title: Project lights/shadows accurately
Post by: zooropa on February 16, 2018, 02:12:42 AM
Hi !

I am trying to replicate the lighting settings of this reference picture:
(http://byfutura.com/site/wp-content/uploads/pizza_01_porta-1.jpg)

I tried with making my own HDR within KS7. I honestly can not find the way to get accurate shadows projecting from one geometry to the other. I mean...I am trying to illuminate the image as it is in the reference in order to get boxes that cast shadow in the next one. The HDR system does not seems to be the way. I am not getting casted shadows from geometry and also the control of the light position (related to itself) it is not possible.

I decided to go for "add geometry--->plane"  and apply emissive. Again the lighting does not seem to be accurate.

I also tried IES lights and diffuse emissive option in materials. ...
(https://i.imgur.com/i5voFlD.jpg)

As you can see the edges of my shadows are totally blurred. Added to this...the shadow casted...does not look at all (please look to the bottom right box) to the geometry casting it. Also the shadow seems not to finish at the edges of the box...but end little bit before the geometry...giving a strip of light...that do not help to realistic lighting.

I am aware that this is probably my lack of knowledge, so I want to clarify this is not a complain! towards KS :)

I just want to know if this is achievable in KS. I would also like to ask you if you have any tips (in case this is possible to do in KS) to understand how is my reference picture illuminated.  Is it one light source...giving all the setting ???

Thanks so much



Title: Re: Project lights/shadows accurately
Post by: Esben Oxholm on February 16, 2018, 04:43:25 AM
Hi Zooropa.

To create sharp shadows like that, you need a tiny and bright light source - whether it is a pin in the HDRI editor or a plane as area light.
I've created two studios showing a solution for both a HDRI setup and an area light setup. Hope it helps you out.

Cheers,
Title: Re: Project lights/shadows accurately
Post by: zooropa on February 16, 2018, 06:18:37 AM
Quote from: Esben Oxholm on February 16, 2018, 04:43:25 AM
Hi Zooropa.

To create sharp shadows like that, you need a tiny and bright light source - whether it is a pin in the HDRI editor or a plane as area light.
I've created two studios showing a solution for both a HDRI setup and an area light setup. Hope it helps you out.

Cheers,

Esben I can not express how happy I am at this moment. Thanks so much, this was really needed.

Also wanted to ask you, is the size of the light giving you the sharpness of the edge in the shadow ? Is it possible to control this ?Thanks

Title: Re: Project lights/shadows accurately
Post by: Esben Oxholm on February 16, 2018, 06:21:46 AM
Quote from: zooropa on February 16, 2018, 06:18:37 AM
Quote from: Esben Oxholm on February 16, 2018, 04:43:25 AM
Hi Zooropa.

To create sharp shadows like that, you need a tiny and bright light source - whether it is a pin in the HDRI editor or a plane as area light.
I've created two studios showing a solution for both a HDRI setup and an area light setup. Hope it helps you out.

Cheers,

Esben I can not express how happy I am at this moment. Thanks so much, this was really needed.

Great! Glad to help. Happy weekends!
Title: Re: Project lights/shadows accurately
Post by: zooropa on February 16, 2018, 06:23:06 AM
Just added a comment above! Thanks
Title: Re: Project lights/shadows accurately
Post by: Esben Oxholm on February 16, 2018, 06:28:26 AM
Quote from: zooropa on February 16, 2018, 06:18:37 AM
Quote from: Esben Oxholm on February 16, 2018, 04:43:25 AM
Hi Zooropa.

To create sharp shadows like that, you need a tiny and bright light source - whether it is a pin in the HDRI editor or a plane as area light.
I've created two studios showing a solution for both a HDRI setup and an area light setup. Hope it helps you out.

Cheers,

Esben I can not express how happy I am at this moment. Thanks so much, this was really needed.

Also wanted to ask you, is the size of the light giving you the sharpness of the edge in the shadow ? Is it possible to control this ?Thanks

Yup, the size of the light source determines the softness of the shadow. The smaller the source the sharper the shadow edge - and the bigger the source the softer the shadow edge. If you want to soften the edge in the scene, simply scale the area light or the size of the pin. Cheers,

I talk shortly about the relationship in this tutorial:
https://youtu.be/21CkXICyhvA
Title: Re: Project lights/shadows accurately
Post by: zooropa on February 16, 2018, 06:30:32 AM
Oh honestly I thought If I change the size of the light it will change the beam sizee too...so ....That is confusing.
Thanks I will experiment now!
Great weekend to you too
Title: Re: Project lights/shadows accurately
Post by: zooropa on February 16, 2018, 08:45:24 AM
Esben there is something strange in the scene. I am not sure what is hapenning but my meshes got crazy.

Can I send you a private mail ? I am not sure if its your scene, mine, or a bug.