[REQ] Backface-Culling!

[zeitmeister]

Hey,
would it be possible to have an option wether polygon normals pointing away from the camera are being rendered or not?
This could help hiding objects from the camera!

[pixie]

Hey,
would it be possible to have an option wether polygon normals pointing away from the camera are being rendered or not?
This could help hiding objects from the camera!

I usually just select the second red ball, which is the object parameter that tells cinema you don't want a given object rendered. But it could indeed in some cases make the workflow easier (it would avoid separating the planes from a wall for example so that they could be hided).

[delle]

I posted a similar message exactly one year ago (see here), but until now... no answer...

[zeitmeister]

Oh... !

I came into it becaus Prof4D asked for it, and then one day later a collegue at my former employer asked for it, too...
He needed the function for an interiour viz, where the camera is situated outside the room, but inside there's a mirror that should show the wall directly in front of the camera.
He wanted to avoid huge perspective distorsions with that...
hm.

[pixie]

What he really want is camera clipping

[delle]

I'd like to have both but, if camera clipping implementation is too difficult to Ono (I don't know how Indigo is implemented internally), I proposed a work around to try to solve the problem (interior rendering of small rooms).

Until now no answer...

Here in Italy we say: "La speranza e' l'ultima a morire"...

bye

Delle

[lycium]

i try to keep off the forums but it pains me to see this go unanswered.

it does not make physical sense for a surface to suddenly stop existing once you look at it from another direction; indigo is a physically-based renderer.

[delle]

i try to keep off the forums but it pains me to see this go unanswered.

it does not make physical sense for a surface to suddenly stop existing once you look at it from another direction; indigo is a physically-based renderer.

...and what about camera clipping? Can be used in a "physically-based renderer" ?

[lycium]

sorry, i don't know what camera clipping is in this context. you mean not showing what's not visible to the camera?

[lycium]

ah, just read your post in the thread you linked (camera clipping == near clip plane). this is in the same family of hacks - making objects conveniently disappear.

consider that in a renderer such as indigo, of central importance is the energy balance in a scene. specifically, if energy is lost or gained in some inconsistent manner, things go awry (this is especially true for MLT since it explores around looking for higher contribution). the classical hacks and tricks of 3d graphics cannot apply here if we wish to keep using the laws of physics.

ps. delle, aren't you one of the lux render devs? if so i would imagine you know this

[delle]

sorry, i don't know what camera clipping is in this context. you mean not showing what's not visible to the camera?

To be more precise, I'm talking about front plane camera clipping. It is a plane that virtually makes invisible the objects between tha camera and the plane itself.

Front Plane Clipping is what you need if you want to render a small bathroom placing the camera outside

[delle]

...ps. delle, aren't you one of the lux render devs? if so i would imagine you know this

No, I'm not a LuxDev man , but I'm currently following three Forum: Indigo, Lux and Yafaray

Maxwell Render has Camera Clipping and it's a Physically based Render... so...

[lycium]

i agree, that's good evidence that it can be done. please don't be too cynical man, nobody has an agenda to suppress anything.

since it's important to you, i'll try to remember to ask nick about it next time i see him.

[suvakas]

Well it's important for archi viz in general, not just for delle.
It's a quite common feature of proffessional renderers in our days.

[delle]

since it's important to you, i'll try to remember to ask nick about it next time i see him.

From the Interior Rendering point of view, this would be the major change to Indigo "core" since 1.1.18 (I'm speaking for myself of course)