Hide from camera/GI/reflection

  • Hi :-)


    Something that I miss a lot, is the ability to exclude part of my scene from a render. In Maxwell render you have a right click option that lets you specify if an object should be visible, hidden in reflections, or included in the calculation of global illumination. Could this be implemented at some point? its not urgent, as there are work-arounds that work :-)

  • It could be implemented. But I'm not sure if I understand the use case. When would you want to exclude something from the GI calculation but still want to have it visible? It then may look like it's drawn on top like a cartoon.

  • a good example could be when you have an element behind the camera (eg. a billboard of trees/buildings), that you want to have reflected in your "hero" element (a facade). but maybe that element behind you is casting a great, big shadow that you want to avoid, but you still want the element reflected :-)
    the same goes for some interior shots... sometimes you have to "cheat" to get the best view, and that means stepping inside a neighbouring room. In that case you want the wall between the rooms to be invisible (so you can get the camerashot you want), but the wall should still be in reflections and GI.

  • +1. I agree, it would be a nice feature to have this in Enscape. I use this capability all the time in Octane Render as well. Most render engines have this capability for the reasons (and more) that Herbo mentioned.


    We use this capability often on lights we want to cast light but not contribute to the scene with reflections that can be seen in objects around the room or hard shadows. Having options to check/uncheck object items like "Camera Visibility", "Cast Shadows", "Relfections/Refractions" etc. would be very nice.

  • That's a very good question. I can only speak to how I've used this in other render engines, which is actually two of the ways you mention which does seem to work well.


    Typically these settings are saved in that specific model file globally. For each new project you'd have to specify those settings again for whatever objects you'd want those features on of course.


    With that being said, Octane has a nice feature that will allow you to also, in addition to the above, save any rendering settings per camera view as well. This works very well for still shots of course, but can be a little confusing when you start doing animations as typically we use camera views here to "direct" where the camera goes (so we have to enable settings like this for the model rather than each camera view). But, for still shots it's great.


    So . . . would it be possible to have the option on whether or not to save these items in the model Globally OR per camera view? I'm not trying to make it confusing, but as you mention, there are Pros and Cons to each.


    Personally, the only option I don't like is Option 3.

  • Just trying to think 'outside of the box' a little bit: could it be simpler to have two advanced view/render options:

    - tic-box to not render shadows from objects behind the camera.

    - have a 'clipping field' sphere/plane at a variable distance from the camera - all geometry between the field and the camera is ignored in the main render, but shown in reflections. (This would cut through walls/geometry like a cutting plane)

  • If the option was within each selected object, then each object would need to be selected and set, then re-set when not wanted - it would also only look "correct" for static images. I was proposing a simpler way (I think) so that you don't need to edit stuff in the native program for a presentation.


    I know you are outlining the way it has traditionally been done in other software, but I don't think that's a reason to be tied to doing it the same way: what are the end results you are looking for? For objects not to get in the way of the scene/view you are presenting, but to be visible in reflections. A more complex method might be to have geometry the camera is enclosed within only have a wire-frame that you can see through; there are other ways to achieve the same goal.

  • I think having it in the material options is a good idea Micha. That way you can use it for any object in the scene.


    It's not just objects behind the camera that are always what you want to hide of course. I've used square planes to block the light from a window reflection on a iPad screen but checked "hidden from Camera" in Octane -- and also checked no reflections/refractions and no shadows on the square plane. That way the ONLY thing the plane is doing is blocking light it's not contributing to the scene in any other way. Quick little tweaks like this cut down on any compositing time needed, especially when you're doing a bunch of shots.


    I think in the end, it's control that you want. To have the ability to choose if an object is visible, shows shadows or not, and contributes to reflections/refractions or not.

  • I feel any other solution than object/material based would cause a lot of coding/UI work and personally I miss a lot of other features. ;)


    I would like to hide emitters/lightblockers from the camera. Also some times I would disable shadows for object in front of windows which slow down the calculation or cause noise (fine fences, light curtains, ...). Also often I need views through walls, but the walls should still block the exterior light and be visible in mirrors.

  • Just encountered a situation where I would want to see an object, but not have it cast shadows - trying to be clever and add a panorama shot to a model so that the view internally is accurate to the site location.

    ... Actually if there was a way to (easily) import panoramas as skyboxes without having to edit them first (define the horizon, take out the sky, set the viewing arc...) that would be amazing.