KeyShot Forum

Technical discussions => Rendering => Topic started by: sqinge on April 01, 2010, 04:51:48 AM

Title: Creating light
Post by: sqinge on April 01, 2010, 04:51:48 AM
Hey!

Does anyone now how to make light, for example a LED-stripe to glow?
And if this is possible, any good materials to recommend?
Title: Re: Creating light
Post by: guest84672 on April 01, 2010, 07:02:14 AM
Import a tube, and map an HDRI to it.
Title: Re: Creating light
Post by: rkulshrestha on April 01, 2010, 07:27:05 AM
Gosh,

Can we have a step by step for this?

Shivani
Title: Re: Creating light
Post by: Chad Holton on April 01, 2010, 09:22:20 AM
Hi Shivani,

Double click on any part you want to change to a "light", change the material type to general, under the texture box, instead of pointing to a jpg, tif, etc... point to a hdr instead. Hope this helps.

Title: Re: Creating light
Post by: Jared on May 04, 2010, 10:18:03 AM
What are HDRs and how do you get them?
Title: Re: Creating light
Post by: Pedro_Julio on May 04, 2010, 01:17:19 PM
HDR stands for High Dynamic Range.

It's basically an image that has radiance data built into it.  Ray tracing programs (like keyshot) can simulate light using that data.  All of the lighting in keyshot comes from the HDR environment images, but you can also apply HDRs like decals.  Any part you apply that .hdr file to will then emit light.  You can find hdr images online or you can even create them in photoshop with a 32 bit file saved as a .hdr.

There are two ways to create light emissive objects though:
1) apply an hdr file as a decal.
2) double click on the object and in the edit window that pops up crank up the brightness of the "ambient" color.
The general material and xray material tend to work best for that.

I'm going to go back and refresh my memory on how to create emissives in photoshop now.
Title: Re: Creating light
Post by: Pedro_Julio on May 04, 2010, 01:34:52 PM
Ok, I remember now.  It's easy.  So basically you are making a decal that just happens to emit light.

Open a new document in photoshop.

You can set the size to be whatever you want really...let's say a 512x512 square.
Set the mode to 32bit.
Click OK.

Once you have that new blank canvas open click on the color selector and pick whatever color you want and move the "intensity" to whatever brightness you want (somewhere between 5 and 10 usually does the trick for me). 
Then click OK. 

Once you are bank to your blank canvas hit Shift+Backspace.  That brings up the Fill option window.  Content should be set to "Use Foreground" by default, but if it isn't set it to that. 
Then click OK. 

Now just save it as a radiance file (.hdr) and use that file as a decal.  Bingo bango.
Title: Re: Creating light
Post by: Ralf-S on May 04, 2010, 03:34:01 PM
I would like to show another "technique". 
( Without PS CS 3/4 ext.)

1- The 3D model with a cut (Moi3D)
2- KeyShot example
Title: Re: Creating light
Post by: sqinge on May 05, 2010, 12:43:58 PM
Nice! Thanks for the tips.

While we are talking about lightning, does anyone have tricks for making regular lights? For example spotlight, lightbulb and other lightning that can be useful for making lamps for example.

Thanks again for all the help!
Title: Re: Creating light
Post by: Ralf-S on May 05, 2010, 05:05:51 PM
As Thomas and Pedro said above, please take a look:
http://www.youtube.com/watch?v=0eKQo_GNObc

Here is an example: "max light+8.hdr"
Title: Re: Creating light
Post by: jlowap on May 07, 2010, 03:02:20 AM
Here are some +8's for you i just knocked up.
Title: Re: Creating light
Post by: guest84672 on May 07, 2010, 05:47:51 AM
KeyShot 2 will have an emissive material - that will make things easier.
Title: Re: Creating light
Post by: Jared on May 11, 2010, 01:42:29 PM
Thank you everybody. 
You helped me a lot!

Jared