hello. Simple question, but I couldn’t figure out. Other DCCs have a ‘Primary Visibility’ attribute on the objects. How do I translate this to UE? What would I do, if I want to turn off the primVis of an actor?
Thanks!
If I have done my research right, there is no one-to-one equivalence in UE.
Please add this in a future release. It is crucial for setting up render layers.
Is there a separate place for submitting suggestions for features like this?
Hi @mrmraw75
You can achieve the same effect as Primary Visibility by setting an object’s attributes to the following:
Visible: Off
Affect Indirect Dynamic Lighting While Hidden: On
Objects with this will be invisible to the camera, but will show up in reflections, cast shadows, and affect GI.
Alternatively, there is a Holdout setting which does the same, but also punches out the screen as black wherever it is visible to the camera.
These both work in Lumen & path tracing.
Thank you @EvanHammel . I just tried and it is not the same thing as PrimVis off, because the shadows are missing.
you want an invisible object to cast shadows? well… this might help. be aware that the object is still processed. it simply doesn’t render in the main pass. works for shadow maps and raytraced shadows. but doesn’t cooperate with megalights.
@glitchered Thanks! At least it is possible. But this opacity mask-thing….it is a hack after all.
And you would already have to do 3 things: the visibility-checkbox, the Affect Indirect Dynamic Lighting While Hidden: On and then hack the material for the shadows? Come on… it could be one checkbox- this is the funcionality of a primary-visibility attribute.
You would have to add this to every single material in your scene. And… with this approach you will most likely encounter problems down the road rendering.
a natural primary visibility is just turn everything off. no object. no gi. no reflection. no shadows. what it seems you’re trying is infact the hack. doesn’t matter if other renderers allow that simple switch. it’s a visual cheat.
what is it exactly you’re trying to do, replicating maya aside? like shadow catcher layers or a seperate reflection pass or complicated compositing chains? well… unreal is primarily a game engine with all in one render output.
I just found this in production the other day, but in 5.6+ you also need to turn on “Hidden Shadow” for the shadows to show up. This should solve your problem, and act just like Primary Visibility.
Yes, you are right. It is a game engine. But it wants to be a render engine as well, hence MRC and all the features added.
If you want to layer your shot for compositing you need a Primary Visibility feature.
5.6+? Thanks! I checked with 5.4 the other day. I will have a look asap.
@EvanHammel I can get it to work with 5.6.1. Probably I’m doing something wrong…
This is the scene.
When I turn hidden shadow on, the shadow appears and also the bounced light inside the shadow.
The reflection is missing and the bounce light looks ‘cut off’ or ‘cut in’. Is this expected behaviour? I don’t have time atm to check it with mrc…
Thanks
have you wondered why it is called ‘primary’ visibility?
no. for a game this is not very relevant, nor performant, to comp aggresively. and… i render in blender. i get all the passes if i need them for comp shots. : )
Looks like there are a few settings that should be changed if you want this to work in Lumen.
Here is a test scene I put together:
You need to set some things on the Post Process Volume to get these effects to work:
Now you can set the sphere attributes:
@glitchered Yes you can do all of these things in Maya, Blender, etc. And yes Unreal is a game engine. However, you must have noticed the trend of Offline Renderer features being added to Unreal for the last several years. The goal is to be able to do product visualization style renders in Unreal, to gain all the benefits of working in realtime. If people are asking questions like these about Unreal, it shows there is interest in those features, myself very much included.
i get that. just not this form of application. to me mrc is like augmented reality. you put a 3d scene in a tracked irl shot. what is the goal of removing a shape in 3d tho? it’s shadows, gi and reflection of something not visible. even if you were to comp in a live plate you’d still have the 3d object there. there’s only one cinematic effect shot i can think off, that looks cool, but also kinda fake. hmm…
ima dip outta this topic. don’t think i can offer help for video production. : )
Thanks @EvanHammel . I really appreciate your support. I will check it out asap.
Yes. That worked fine. I still think it would be a good idea to introduce ‘primary visibility’, but maybe the idea would collide with other principles of the editor.
Thanks a million.