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Image Projection to Back of Glass Orb...


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Hey all, happy to be here with a question and guidance. I've searched for a couple of days and can't seem to figure this out,...

 

I currently have a simple glass orb that that will be snow globe esque with objects inside. I'd like to project an image on the inside as a scene that will rotate and move with the orb itself (not sure the correct term for this sorry).

Don't have access to the c4d file currently but I'm good with instructions and can dive in when I'm back at the PC.

 

Appreciate even the reading of this!!

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We need to clear up with your model should be hollow, like snow globes are (or filled with liquid for example) or if you are trying to make a purely solid glass sphere. These things are not the same, and nor is the 3D approach to making them !

 

If you are building a snow globe, you need to build it as they are built in the real world - ie you'll be needing a HOLLOW shell with wall thickness, not a solid glass orb. Both Cinema and RS will see a sphere as being solid unless it has internal walls, which means light won't behave as you expect, hence its importance.

 

But once you have that built, it is a relatively trivial process to select a section of the internal wall, and split that off into its own separate object, and given its own (tiny) thickness so it can be easily textured with whatever you want to use as a background. that would then sit just inside the inner walls of your sphere.

 

Whereas if we are building a solid glass orb, then the same strategy applies but you don't need the inner walls. however you DO still need the separate background object to hang inside it.

 

I was confused by the next bit of your question - you want to 'project' an image somehow ? how is that different from just applying a texture to the background surface ? Will need some additional explanation there to understand what you mean - the backgrounds of these things are usually static, so don't move in relation to the container... perhaps you mean something else ?

 

Photo reference is always helpful if you can't provide a scene file... perhaps you could upload some of that ?

 

CBR

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Thank you so much for the detailed reply, happy Monday!

I've attached the working file here for reference...

 

In re to the globe: I've gotten hollowed out using a cloth surface object and added thickness to it. I have a "floor" inside the globe that'll be water eventually (fingers crossed).

To try and clarify where I'm stuck: I have an image (also attached) that I'd like to have act as a background image inside the globe, like an inner wallpaper, but when the globe moves or rotates, and subsequently all objects within, the image will always appear to be static.

 

I feel like this is something for camera mapping perhaps?

Glass Orb.c4d

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  • 4 weeks later...
On 7/19/2021 at 10:29 AM, jaharoni said:

Thank you so much for the detailed reply, happy Monday!

I've attached the working file here for reference...

 

In re to the globe: I've gotten hollowed out using a cloth surface object and added thickness to it. I have a "floor" inside the globe that'll be water eventually (fingers crossed).

To try and clarify where I'm stuck: I have an image (also attached) that I'd like to have act as a background image inside the globe, like an inner wallpaper, but when the globe moves or rotates, and subsequently all objects within, the image will always appear to be static.

 

I feel like this is something for camera mapping perhaps?

Glass Orb.c4d 320.14 kB · 0 downloads

Wanted to bump this in hope of finding a solution. Appreciate any guidance 🙏

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Oh right, you want the background to appear static and the same regardless of the rotation or position of the containing sphere ?! Won't that look at best wrong, and at worst awful ?! 🙂 Or perhaps I am still misunderstanding - originally I thought you wanted the background to behave physically correctly like you find in real world snow globes - ie the BG is fixed within the globe, but you can still see it (not identically) from most angles due to the refractive qualities of the case.

 

But if you want it to look front-on, regardless of where you view the snow globe from, then I don't see how that's possible, without further cheating physics !

 

Sure, camera mapping would get you that result, but only when you are viewing the surface it's projected onto - if you moved round to the side of the snowglobe, you would surely only be able to see half the background plate ? And how could you predict what the refraction of the glass would do to the camera mapped background ? And if you are round the side, are you expecting to see the frontal view of the background in the globe ? So many questions ! Man I am not understanding this AT ALL ! 🙂

 

CBR

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Grandmaster suits you v v well, all good points you bring up. I honestly am messing with ideas to challenge what is perceived as visually incorrect but I fear that my ideas are just that sometimes.

Let's start simple and get the image projected to the inside of the globe. I can manipulate the entirety of the sphere to rotate with a camera projection which would have the desired effect but in a visually coherent way. The sphere will be resting/floating on a hand with a transforming object within it, the background image is serving as a scene to add depth and dimension to the overall object.

You definitely understand and I can't thank you enough for your time in unraveling my mess 😅

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I think I understand what you want, but I can't open the file with my old version. Example attached is pretty straight forward, but here is a quick description:

 

Use a sphere set to hemisphere that will fit precisely within the globe's inner surface. Add the background material to this - camera mapped. Make is a child of the globe. Put a 'Look at Camera' tag on the background object. The background will now always face the camera no matter how the globe moves.

 

But I may not fully understand the end result you want. I didn't test with refraction, but as it is contained within the globe, it should be a uniform distortion, not wonky.

 

If you get it to work, I would love to see the result!

 

 

Globe Example.c4d

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