How to set focus behind glass?

[steveps3]

I'm trying to render a scene but I want to set the focus on a object that is behind a pane of glass. Without working out the actual position of the object that I want to focus on and manually setting it I can't find any way of achieving this. Does anyone know of a technique for changing the focus to something that the focus picker won't "pick"?

[LudovicRouy]

Did you try to "delete" (or deactivate it if your 3D software allow that) this glass, export your scene to octane, select the object you want to focus and save octane scene then re-export your complete original scene (the one with the glass) when you do that it will re-use the focus you've just saved...

[matej]

Just an idea to try, not sure if it will work: apply a portal material to the glass, pick the object, then reapply glass.

[steveps3]

The portal trick didn't work, it still focuses on the portal. Looks like I will have to do the double load trick instead. I don't know why the auto focus doesn't work like the material selector whereby it gives you a list of options if you right click.

Maybe there needs to be a new option on the node "do not focus upon".

[kavorka]

Did you try rotating the camera to an angle where you can see the object, then go back to your original place.

Or you could just set to DOF position in your 3D modeling software before exporting.
(I do this with Blender)

[steveps3]

I know that the whole camera control is so much better in Blender but I would like to hope that Octane would have the ability to focus on something other than whatever is immediately in front of the camera.

The scene that I am rendering is a greenhouse which is entirely enclosed in glass. I was trying to focus on something inside the greenhouse. I'd not quite decided what would be the best view so I was experimenting. Obviously not an easy thing to do when you can't get the camera to focus.

What blender needs in an integrated render solution but I guess that will never happen. The price we pay for having open source software.

[matej]

What blender needs in an integrated render solution but I guess that will never happen. The price we pay for having open source software.

Cycles is happening and will happen (probably much sooner than Octane 1.0, too )

Also, cant you "enter" (zoom in) the greenhouse with the camera, pick the object and exit back?

EDIT:
Another solution: when you export the scene, set the camera inside the greenhouse. In Octane you then pick the object and zoom out. When you need to select another focus point, click the camera position reset button, which will put it back inside. Repeat.

[abstrax]

I know that the whole camera control is so much better in Blender but I would like to hope that Octane would have the ability to focus on something other than whatever is immediately in front of the camera.

The scene that I am rendering is a greenhouse which is entirely enclosed in glass. I was trying to focus on something inside the greenhouse. I'd not quite decided what would be the best view so I was experimenting. Obviously not an easy thing to do when you can't get the camera to focus.

What blender needs in an integrated render solution but I guess that will never happen. The price we pay for having open source software.

You can always disable auto-focus and then set the focal depth manually. By increasing the aperture you increase the DOF effect which gives you a better indication about where the plane in focus is.

Cheers,
Marcus

EDIT: The reason why the focus picker isn't working like material picker is, because no one has thought about this yet I put it on our to-do list.

[steveps3]

This was only part of a much bigger scene anyway but whilst I was modelling the green house I thought that I'd get some WIP renders.

Here is the scene. I was trying to focus on the seedlings.

[kavorka]

What I meant is that I set the focus object in blender and I believe it exports it as part of the camera when I bring it into Octane.
(at least it seemed to work that way before, unless it just randomly worked how I thought it would have)

Did you try the option of zooming in past your glass and selecting the object for focus and then zooming out? I think I tried this before but if I remember correctly, the focus got weird when I zoomed back out.

Let me know if you tried these already, I'm curious if I'm completely wrong.