KeyShot Forum

Technical discussions => Lighting => Topic started by: fario on December 21, 2011, 05:14:30 AM

Title: top view - chrome - to give life
Post by: fario on December 21, 2011, 05:14:30 AM
Hello,

when working with shows a top view, it is difficult to give life to objects that are flat and shiny, like chrome, etc...

like the hands of my watch.

you have a solution for me?

Thanks.

Antoine
Title: Re: top view - chrome - to give life
Post by: guest84672 on December 21, 2011, 06:21:37 AM
It all depends on your lighting. Change the lighting environment - KeyShot 3 has many environments that don't give you the strong or any lighting from the top.
Title: Re: top view - chrome - to give life
Post by: br3ttman on December 21, 2011, 02:59:16 PM
Antoine, I understand your dilemma.  Sometimes I wish I could also tilt the environment in addition to rotating it in order to dial in a highlight highlight or pull out the material character without having to add additional items to my scene.  Maybe a future build of Keyshot could allow for tilting the environment, too?
Title: Re: top view - chrome - to give life
Post by: guest84672 on December 21, 2011, 03:00:49 PM
Yep - tilting is on the roadmap.
Title: Re: top view - chrome - to give life
Post by: br3ttman on December 21, 2011, 03:09:11 PM
Cool!  Would the floor stay fixed?  i.e. just rotate the HDRI sphere?
Title: Re: top view - chrome - to give life
Post by: Ed on December 21, 2011, 10:42:42 PM
"... Yep - tilting is on the roadmap."

I think everyone, especially jewelers, would love to see that.  Sometimes you just can't quite get the desired lighting by rotation alone.

For example, when I render domed reflective rings, I usually get a weird area on the top that, as far as I can tell, is caused by the point of the HDR where it wraps together (the North Pole?)  I think if the HDR has any kind of a transition in luminosity where it wraps, you get an un-natural lighting artifact.  At least that's what it seems to be.  I've seen it on several models using several HDRs.  So, I think being able to tilt that North Pole of the HDR away from the top of the object would be great.

Ed
Title: Re: top view - chrome - to give life
Post by: PhilippeV8 on December 21, 2011, 10:51:31 PM
Ed, looks to me that those are just bad HDRI.  Indeed tilting can help .. but if you're not carefull you'll get that same reflection somewhere else then.
The top of the HDRI just has to come together nicely.
Title: Re: top view - chrome - to give life
Post by: guest84672 on December 22, 2011, 06:07:59 AM
Yes that should not happen with a good HDRI.

@br3ttman - yes the floor HAS to stay fixed. It's useless otherwise.
Title: Re: top view - chrome - to give life
Post by: Ed on December 22, 2011, 10:37:21 AM
"  ... Yes that should not happen with a good HDRI"

I agree.  However many HDRs (at least those I've collected from various sources) do this. 

For that reason, I'm looking forward to the ability to tilt the HDR.

Ed
Title: Re: top view - chrome - to give life
Post by: Robb63 on December 22, 2011, 10:39:17 AM
Even ones I've made in HDRI Studio will sometimes do this. There must be some no go areas in the HDRI to keep things out of to rpevent this, I'm just not aware of them.
Title: Re: top view - chrome - to give life
Post by: Zander85 on December 22, 2011, 10:47:40 AM
Tilting the environment would be nice. I suggested this feature myself some time ago, but in the mean time just rotate your model and make sure you have something dark in your HDRI to make that chrome come alive.
Title: Re: top view - chrome - to give life
Post by: fario on December 22, 2011, 02:04:17 PM
the ideal?

to have several hdri in the same scene!

as I can, choose a hdri for my hands and one for my diamonds.
Title: Re: top view - chrome - to give life
Post by: guest84672 on December 22, 2011, 11:28:31 PM
Why don't you use a plane, apply an emissive material, and then make it invisible to the eye?

Or hide the entire watch except for the hands, and render them in a separate lighting environment with alpha channel, and then compose the image in the PS?
Title: Re: top view - chrome - to give life
Post by: fario on December 23, 2011, 12:35:42 PM
QuoteOr hide the entire watch except for the hands, and render them in a separate lighting environment with alpha channel, and then compose the image in the PS?

yes it is the right path

Antoine
Title: Re: top view - chrome - to give life
Post by: Speedster on December 23, 2011, 12:53:23 PM
I agree with separate render passes.  Add in a clown pass as well.  But don't forget to lock the camera!!!  Looking forward to what you come up with!
Bill G