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Diable Channel Lighthing in Image Based setting

Posted: Wed Aug 20, 2008 9:39 pm
by Brian_Law
Hi Everyone,

I am new with Maxwell in Rhino and I am very keen in learning it, and hope someone will help me here.

I tried using HDRI as the Image Based setting, under this tab, what is the main function of the "Disable Channel Lighting" ? What are the differences if i set Disable Channel Lightning as None, Sky Dome and Physical Sky? And when should i use it?

Thanks.
Brian

Posted: Wed Aug 20, 2008 9:46 pm
by Mihai
If you disable any of the HDR channels such as illumination, reflection - you can decide if these disabled channels should be replaced by another type of lighting, skydome or physical sky, or not use anything. So for example you can light your scene using HDR maps for all channels except illumination and use Physical Sky for illuminating your scene.

Posted: Thu Aug 21, 2008 1:40 am
by Brian_Law
Thanks Mihai! Great,I will test it out.
:)

Anyone also knows anywhere that I can learn more about adjusting the settings for the Environents Setting Tab, esp. on the image Based section. For e.g. how do i accurately adjust the Instensity, Scale U/Scale U/, Offset U/Offset V and ScreenMapping as my lighting when i used HDRI

Posted: Thu Aug 21, 2008 2:02 am
by JDHill
Hi Brian,

The quickest way to get up to speed would probably be:

1. make sure you have a perspective viewport open to work with
2. if you don't have the plugin's Environments toolbar open, go to Main Menu > Maxwell > Plugin Windows > Show All Toolbars
3. right-click the first button (tooltip: Browse for Background Map)
4. choose an .mxi, .hdr, or .exr in the dialog

At this point, you should have a map showing in the viewport. If you look in the Image Based section of Environment Settings, you should see that selecting this Background map has populated all of the channels with the same - this is the case if the Link Channels option is enabled. Now, you can left-click down on say, the Scale U parameter, and roll the mouse up and down...you should see the changes you are making show up in the viewport (note, the plugin does not show the effect of a screen-mapped Background channel, so you would have to handle that manually).

Let me know if this helps much...

Posted: Thu Aug 21, 2008 2:39 am
by caryjames
I don't know if it helped Brian but it helped me :)

Posted: Thu Aug 21, 2008 7:48 pm
by Brian_Law
Great it helps, JD! Now I can have a better understanding and control over my HDRI as the ligthing source.

Another qns to ask. Do people use Emitter together with HRDI as lighting? I can see from the Mawxwell gallery that there are many awesome rendering that seems have HDRI as the lighting source as also the use of maybe emitter to lit up some parts of the product. For e.g. under household > Hyltom has a great rendering for his stand mixer-2007. Does he use soely HDRI as the only lighting source?

I will post more questions to Hyltom regarding his awesome renderings, and i am willing to invest time to learn from him.

By the way, I am doing industrial design and I am rendering household products most of the time.

Thanks!