[acrighton]

Hi,

Please excuse the 'newbie' question here, I just purchased Maxwell, moving from Brazil for Rhino, and can find no reference on how to correctly use a backplate with the matte material for receiving shadows. I've played around as much as I can with the various settings, but can't figure it out. Is there any 'idiots guide' to doing this correctly?

Any help would be much appreciated. Thanks in advance.

Alan Crighton

[JDHill]

I am not exactly sure what you mean. Basically, you enable Matte and/or Shadow in a material, then apply that material to geometry. The Matte switch will cause the geometry cut out everything behind it, revealing whatever environment is visible there. The Shadow switch will cause the geometry to be considered in the shadow pass, which is a separate image output, and is enabled in Scene Manager > Output > Channels. In Maxwell Render, you'll see the shadow pass if you hover your mouse over the "S" button near the lower left of the viewing area. As I say, I'm not clear on what you're doing, and I'm not an authority on compositing, but perhaps this info will be helpful. At any rate, I would recommend asking this question in the main Maxwell Render forum, since it is not plugin-specific. You might also want to read through this, if you haven't already.

[acrighton]

OK, appears what I'm attempting to do is add a ground shadow as shown in the link you provided, but needs to be enabled in the render channels. I'll play around with this and see what I get it to do. It's very much different than what I've been used to in Brazil, and like any software package, it takes a while to learn. If I can't figure it out via this, I'll post in the Maxwll Render forum.

Many thanks for the very prompt response.

Regards
Alan Crighton

[hatts]

Unfortunately the only way to get a floor shadow with full color is through the diffuse/specular Render channel.

So then your choice to make:
1. Render your whole image flat in one pass, floor included, losing the ability to separate your subject from background
2. Enable "Shadow" for your floor, and include the Shadow channel in your render output. You'll get a grayscale shadow which you can then colorize if desired. You may also have issues with antialiasing
3. Do two full renders, one with the floor hidden from camera and the second with the subject(s) hidden from camera, then composite. This will give a perfect result but takes a while

[acrighton]

Matthew,

Thanks. I was hoping for a simple(r) solution in Maxwell to using a standard backplate image and matching HDRI, much as I have been doing in Brazil for Rhino. This is a fairly common task/need, especially in automotive type renderings, or simply having to place some model in a real world environment. I was hoping the render and shadow channels would magically 'blend' the images into one with the output mode set to embedded, doesn't appear this is the case. I'm no expert in compositing, and was hoping there would be an easy work around without having to resort to doing it all in Photoshop, which I don't currently own and would rather not drop the money on if I can help it, not to mention the associated learning curve.

I'll post into the general Maxwell Render forum to see if anyone has an easy work-around, as this is something that has to be done fairly regularly.

Regards
Alan Crighton