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Shadow Catching Process

Posted: Fri Mar 29, 2013 3:41 pm
by ericg
t_3 and All,

Sorry if I missed this but what is the shadow catching process/procedure for the Daz Plugin.

Thanks in Advance

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 3:52 pm
by Isotemod
Shadow catcher is a diffuse material that has the "matte" switch turned to on.

I believe that it only catches shadows from mesh emitters and images used in the HDR environment.

This is an example of the shadow catcher

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 4:12 pm
by ericg
I got that shadows if I want to render the entire image at once. However, I need it via the alpha channel for compositing with other images.

Look at page 117 of the Octane render manual to see what I am trying to accomplish.

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 4:35 pm
by ericg
Got it!.

Basic Setup.

1. Create a new plane (in this case representing the ground) to recieve the shadows. Set the material to matte.
2. Set Environment to HDR Texture Environment in the Lights Tab
3. Turn "alphachannel - ON" in the Render Settings Tab
4. Add your objects to the scene to cast the shadows
5. Create a sphere or other primative. Set the material emmission to "blackbody" (optionally set your power and temperateure).
6. Position your new "light source" where you want the light and shadows to occur. Move it out of the render frame.

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 4:39 pm
by Isotemod
ericg wrote:I got that shadows if I want to render the entire image at once. However, I need it via the alpha channel for compositing with other images.

Look at page 117 of the Octane render manual to see what I am trying to accomplish.
Part 3 on page 117 explains which options to have on/off.

These options are found on the render settings tab in the plugin

EDIT was a bit late with reply

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 4:47 pm
by Isotemod
ericg wrote:Got it!.

Basic Setup.

1. Create a new plane (in this case representing the ground) to recieve the shadows. Set the material to matte.
2. Set Environment to HDR Texture Environment in the Lights Tab
3. Turn "alphachannel - ON" in the Render Settings Tab
4. Add your objects to the scene to cast the shadows
5. Create a sphere or other primative. Set the material emmission to "blackbody" (optionally set your power and temperateure).
6. Position your new "light source" where you want the light and shadows to occur. Move it out of the render frame.
If your not putting a HDR image in the environment then I would suggest picking "no environment" in your part 2.

When your creating an emitter I would strongly suggest creating a surface that has as few faces as possible and due to a "bug" in final render mode make sure the scale of the primitive is 100%.

One trick I would suggest with mesh lights is to parent them to a new camera and position it slightly behind it. This makes positioning mesh lights really easy.

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 5:13 pm
by ericg
Isotemod

I appreciate all the feedback but this is why I said I am looking for the process/procedure.

i.e. step by step. It is easier for people to try and it is easier to improve steps (like you just did). So if you know the idea way. Detail out a procedure for myself and others to understand.

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 5:15 pm
by ericg
BTW rendering with No Environment produced this

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 5:40 pm
by ericg
Looks Like I only need the blackbody light source with HDR Texture Environments.

You can skip steps 5 & 6 if you use the Default Daylight Environment.

Looks like I am answering my own questions LOL!

Re: Shadow Catching Process

Posted: Fri Mar 29, 2013 6:02 pm
by Isotemod
ericg wrote:BTW rendering with No Environment produced this
Isnt that because your light source is only hitting one side of the cube....