How do I do this?

[spartan00j]

Hello, I'm trying to get this effect. I have a model inside of another model. When I render I want to show the inside model perfectly. As if it was always on top. If that makes any sense. See attachment.
I know I can render them out separately. But I just wanted to check and see if there's an easier way. Again I want the inside model to be displayed through the outside model. The red spear is inside the White sphere.

[Zay]

Paint a transparency map? You can then control it with a dial.

[spartan00j]

Paint a transparency map? You can then control it with a dial.

Sorry, I don't understand. Can you clarify?

[Zay]

If you want to look through a solid object you need some kind of transparency. A transparency map can do that.

[spartan00j]

If you want to look through a solid object you need some kind of transparency. A transparency map can do that.

I know about transparency map. I need to clarify it more of what I'm trying to do. I have two objects. One object which is a square inside of a larger Square. I don't want to add transparency to the larger Square. Because I don't want to see what's behind it. Instead I want to just show the red smaller Square inside of the larger one. But not have the larger Square transparent. Sort of letting the Red Square peek through the larger Square. I know I can achieve this by rendering the models out separately. And one have an alpha Channel. And combine them in post. But I'm trying to eliminate steps if possible.

[Zay]

Then I'm not sure what it is you want. With a transparency map you can control where you want to see inside the box by translate the map or resize it. You can also try the "Clipping material" on the object as you can't get around some kind of transparency _if_ you want to see something behind a solid object.

[frankmci]

What you are trying to do would normally be done in a composite, but you might be able to accomplish this with a cleverly constrained boolean material/object, such that the hole is always pointing directly at the camera and perfectly fits the bounds of the inner object, revealing just the part of the interior you want visible. It really depends on how complex the geometry of the inner object is. I'm assuming spheres and cubes are just simple examples.

You might explore the AOV system along with render layers to accomplish this, essentially executing a multi-render composite but doing it all in one go. It seems like the sort of thing that might be able to handle, but I honestly haven't had the time to understand the Ever Expanding Power of AOVs over the last few releases. I may also be thinking of stuff that's happening with the Octane 2024 Alphas.

[spartan00j]

What you are trying to do would normally be done in a composite, but you might be able to accomplish this with a cleverly constrained boolean material/object, such that the hole is always pointing directly at the camera and perfectly fits the bounds of the inner object, revealing just the part of the interior you want visible. It really depends on how complex the geometry of the inner object is. I'm assuming spheres and cubes are just simple examples.

You might explore the AOV system along with render layers to accomplish this, essentially executing a multi-render composite but doing it all in one go. It seems like the sort of thing that might be able to handle, but I honestly haven't had the time to understand the Ever Expanding Power of AOVs over the last few releases. I may also be thinking of stuff that's happening with the Octane 2024 Alphas.

Okay will do. I'll just play around with settings.