Help with Canvasses and rendering layerable characters

Cyrinadia

Hello, me again.

I have a couple of questions:

One: What is an alpha map in Canvasses and how does it work? Something to do with transparancy.. but it renders all black?

Two: I have a scene, a coffee shop interior, where I need to retain the light dome, environment, and emissive lights and textures. I want to eventually add multiple characters to the scene, but know my machine struggles with 5. How can I put each character in the coffee shop scene, but render only the character and their interacting with the scenery (like standing behind a counter for example)?

     Like: I rendered the empty shop and saved. I put a character in behind the counter. I want to render the character but not the entire shop, though I need the lighting setup kept (model built-in emissive globes, 2 exterior emissive planes, plus the coffee shop hdri lighting on the environments tab) and since the lights are outside, the walls and roof have to remain in place.

I really hope this makes sense.

 

Thank you

 

chris-2599934

Here's how to do it with canvases...

• Shoot the shop normally without and characters (visible) it it.
• Add and pose a character. Create a canvas, it should have a type of "beauty," the "Alpha" box should be checked and the Node List should include the character, their clothes hair eyelashes etc.
• Render the image with the lighting etc. unchanged. You'll get the character rendered with the lighting falling on them properly, but any part of them hidden by the environment (as well as the environment itself) will be transparent.

That does what you asked for, but there's a big problem with it: although the rendered character is affected by the environment, the reverse is not true. So if your character is sitting on a chair and casting a shadow upon it, the shadow will not be rendered on the canvas. This may or may not be an issue, depending on your scene, You might be able to work around such a problem by including the chair in the node list.

As an alternative, lay out your scene with its characters, make the characters invisible (I like to put each character in their own Group, which makes this easy). Do a render of the empty shop. Make one (or more) characters visible. Select the Spot Render tool, go to the Tool Options panel and set it to render to a new window. Drag the marquee around the character(s), including the space around them for any shadows they may be casting - it'll render just that part of the picture, but in an image the same size as the full shot - the rest being transparent. You can then combine them in post.

Cyrinadia

Cheers, Chris. I think I will try both styles. I did the nodes, but as an alpha without the beauty canvas. Thanks again

 

Am doing it now and you are my render hero. Thanks a heap this was exactly what I was looking for