Shadow Channel PDF Tutorial

Fri Feb 27, 2015 2:59 pm

Dear friends,

at the following link you can see a new pdf tutorial that explains the Shadow Channel.
You can find details on how to generate this channel from inside Thea Studio and from Live Plugins: 3dsMax, Cinema4D, SketchUp.
At the end of the tutorial you will see some steps in order to use this channel along with Mask Channel, in post processing, to generate images with transparent backgrounds and shadows reserved.

Link: https://www.thearender.com/resources/Shadow_Channel.pdf

Tip: you can right-click on the link and select the "Save Link As" option to download the pdf.

Note: Mask Index within SketchUp, will be available from the very next plugin revision in some days.

Sat Feb 28, 2015 12:57 am

Nice tutorials! Thanks a lot

Sat Feb 28, 2015 5:32 pm

Can this be used as ambient occlusion? No need for the mask channel... just put the color and shadow channel together in photoshop and set the shadow channel blend mode to multiply?

Tue Mar 03, 2015 11:33 am

christina wrote:Dear friends,
Note: Mask Index within SketchUp, will be available from the very next plugin revision in some days.

it is not available yet isnt it? Anyway it is not working in my version "TheaForSketchUp_v1.4.04.254.1252": right clic get nothing

Tue Mar 03, 2015 12:43 pm

rogerpenna wrote:Can this be used as ambient occlusion? No need for the mask channel... just put the color and shadow channel together in photoshop and set the shadow channel blend mode to multiply?

Everything is possible depending on what you need to produce

The mask channel will help you to isolate models and/or shadows in general, this is why it is presented here. In this way for example you can use only the shadows on the floor and not the shadows from a model to another.

Tue Mar 03, 2015 1:01 pm

archigrafix wrote: it is not available yet isnt it? Anyway it is not working in my version "TheaForSketchUp_v1.4.04.254.1252": right clic get nothing

It will be fully available within a few days; as you see from the screenshots it is already implemented in a beta version.
We shared the pdf though to cover the plugins and studio. So only some days patience

Tue Mar 03, 2015 1:57 pm

rogerpenna wrote:Can this be used as ambient occlusion? No need for the mask channel... just put the color and shadow channel together in photoshop and set the shadow channel blend mode to multiply?

That will make the objects darker because the color channel already has shadows and you're adding them again when multiplying the shadows layer with the color channel layer.

Tue Mar 10, 2015 6:30 pm

well, I saw in some tutorials the Ambient Occlusion pass from VRAY being used that way, blended inside PS with the rendered color image and the result is pretty cool. But yes, I guess there is a big difference between an AO Channel and a Shadow Channel. The AO Channel supposes the us of Ambient Light, thus shadowing only dark corners, crevices, etc.

Tue Mar 10, 2015 8:10 pm

rogerpenna wrote:well, I saw in some tutorials the Ambient Occlusion pass from VRAY being used that way, blended inside PS with the rendered color image and the result is pretty cool. But yes, I guess there is a big difference between an AO Channel and a Shadow Channel. The AO Channel supposes the us of Ambient Light, thus shadowing only dark corners, crevices, etc.

That's the difference. What you describe there is a very handy way of finetuning the AO pass in post processing.

If you're interested try making a diffuse pass, a AO pass and a shadow pass, and mixing all of them.

This would look like a pimped up sketchup render.

If you mix it with reflections it's very cool.

If you consider that in post you can control each of those parameters manually, you can get an unbelievable control on your final image later.