3D scene mapping

[lorenart]

hello everyone 🫶🏻 I need some help - Im having some issues with mapping a 3D shape

I have a transparent cube in a room
my 2 projectors need to be the 2 cameras on the same scene
so that I can develop 3D shapes and scenes inside the cube while there is full projection coverage

in TD I made 2 cubes with the same proportions as the physical cube (1.5:2 - 3h), I am rendering them in 2 renders with 2 outputs in each of the projector (with WindowCOMP)
(so I can move the 2 cameras individually) but the scene has the same center

I cannot match the same center moving the cameras…
and of course when I move the camera I sometimes also zoom so I mismatch the cubes

It looks so easy and difficult at the same time-
Is it a geometry issue?
Should I be really precise with life-size measurements?
Is it an issue with the cameras?

C_cameratracking.toe (501.9 KB)

[jacqueshoepffner]

Hello,
I think I understand what you want but your drawing must be more precise, exact location of camera, projector throw and shift etc.
I propose you my technic:

• modelise the box in Blender, create UV mapping texture and FBX structure
• import in TD, replace phong material with constant material with the same texture
• place the cameras at the right place, throw, shift etc.
  Projecting the image, you can make the last setting on the projector or inside TD.
  Long time ago, I had published a tutorial about UV unwraping in Blender.
  Have fun
  
  
  
  http://hoepffner.info/TouchDesigner/3DsceneMapping.zip
  https://derivative.ca/community-post/tutorial/unwrapping-uv-blender-28-use-touchdesigner/62532

[leclaire]

Hello,

Looking at your project I think you may want to separate your larger overall problem into two smaller and more easily solved ones:

1. Rendering and re-projection of the 3D scene on to the cube geometry (virtually)
2. Projection mapping of the resulting textures on to the cube geometry (physically)

To answer what you need for #1 - what is the content and how / from where does the audience view it? This will dictate the context from which it should be rendered and re-projected on to the cube geometry. For #2 the mapping of the result is trivial with established mapping workflows found in camSchnappr or other projection mapping workflows in TD.

[lorenart]

Hi Jacques, merci beaucoup for your answer!
I think I am mainly missing the precision in real life measurements and the TD setting up of the correct parameters
I think you can see my inexperience ahah

I set up the 2 projectors in the only way I can test this scene in my room
projector A. mounted on the ceiling facing upwards to cover the top
projector B. on a shelf facing a bit downward
and this is how the scene looks like:

@jacqueshoepffner

place the cameras at the right place, throw, shift etc.

Related to this and to your tutorial for example - how did you set up your target1 and target2?

C_cameratracking.26.toe (502.1 KB)

I was able to map the scene, mainly moving my cam1 and cam2 with the active viewer - but I dont think it is the correct final solution
maybe I missing some basics considerations or notions (related to a 2 projectors set up within TD)