Occluding objects

Hi All,

Not sure which category I ought to use, so sorry!

Imagine a room with 2 characters in the middle.
In the room are a few objects - table, chairs with a clock and pictures on the walls, etc.

Now, in the view port (2.79 nightly) I will rotate the view to obtain the shot I want.
BUT, when I do this the walls and other objects get in the way.
Now, I am fine with using the “Backfacing” output to switch to a transparent shader on the walls, but that still leaves other object occluding the view EG pictures or a clock on the wall.
Applying the same backface culling to ALL the other objects would be too much.

So, to the question, is there a way to use the backfacing wall parameter to switch off nominated objects?
Or is there another way you could do this?

(I have found that perspective mode - keypad 5 - helps a lot but not always)



in 2.8 eevee you can set backface culling per material in the material settings

Unfortunately Eevee doesn’t have material override, which would enable using Geometry/Backfacing to shader mix between diffuse and transparency shader. I use this a lot in Cycles for room geo I make myself. I also have a utility node group I can slab at the end of my materials to make backfacing faces transparent this way (usually for camera only). This is okay for own geo and if material count isn’t that high.

But today I had an ifc import (using 2.79 for that - save immediately - just saying) of an office floor with thousands of objects, hundreds of which were slab (box) category for the ceilings (with tons of materials as well). Navigating is hopeless, even just to find the right room/area you’re looking for (slabs in the way from above). I forgot to check (will try tomorrow), but maybe you can select troublesome pieces, hit invert selection, and multiapply object/viewport display/in front. Working with that many objects using global xray is just a mess, I wish I could enable xray only for selected objects.

Another option is to set it to show as wire or bounds. It wouldn’t work in my case as I had to see my own objects in reference to the slabs.

Or open a secondary view in wireframe mode to position the camera manually. Works if all you need is set the camera, but not as a viewport orientation tool. In addition, you can also use walk or fly mode, bind whatever you need to a key. This is by far my preferred method of getting around spaces that is more than a simple room.

If you do a lot of interior stuff, I suggest you change all the default cameras to a wider field of view (possibly also clipping values that makes more sense), and save it as default. Default of 50mm focal length is decent for character work, but nuts bad for trying to navigate interior spaces. I use 12-18mm for viewport cameras, I keep rendering cameras separate.

Just for viewport, or for Cycles renders?

For the viewport, if you want something out of the way, it’s best to use local view, or an alt-b box.

For rendering, don’t even worry about backfacing. Instead, if you want a see-through hole in your environment, mix with a transparency shader based on the distance between worldpos and an empty. You can create a single node group, with a combine XYZ node with a driver attached, and pop it onto the end of any material you want to make a hole into.

can you put some objects on other layers ?

happy bl