Hello
I have a potentially non-specfic c4d question but where maybe c4d could help?
I’m rendering out content for a circular screen. The screen has a very wide resolution (about 13k pixels) and is 1080 pixels tall.
When I work on the content in C4d or After Effects, I essentially work on an “unwrapped” version of this screen that is just a straight “strip”.
I have some content that needs to wrap around the screen and basically travel around it several times. I’m creating some moving lines using particles that go from one side to the other, and then need to continue moving across the screen.
When I work in my “flat” version, of course the content hits an edge, and when this projected on a large screen, there will be a “beginning” and an end to the image.
What I’d like to do is find a way to render this out of C4d in a way that allows the content to perfectly loop around.
I’m wondering if there is a solution like having a spherical camera that outputs the content “unwrapped” but captures it moving around the projection surface.
I hope this question makes sense. I don’t have a project file because it is more of a theoretical question. As an illustration, in After Effects I use the Offset effect to move some items across the screen. Whenever they hit the right edge, they appear on the left edge. But with content that takes up the whole screen, this doesn’t work.
I just tried with a spherical camera inside a tube, and it does what I need to a certain extent.
I can see this camera wants a sphere, not a “slice” of a sphere.
So is there a way to “unwrap” something that is being created on a circular object?
I’m not clear how the final projection is made. Is it a sequence of screens, or is round canvas, thinking about practical camera mapping or just creating an infinite texture.
If the filmstrip needs to be “orthogonal”, then the Cylindrical Lens would be the way to go. Imagine a vertical axis, as long as set into the Render Settings. This will have only horizontal “rays” to its context.
The other way is to set up a Spherical lens, which will keep a central point and has, therefore, a “magnifying effect” to anything closer in both image-axis, the Cylindrical lens will not change the vertical size.
If your object is a cylindrical shape anyway, both should create the same result. If you A/B the renderings of both Project files, you will see a difference. OR just have a look which one cuts the top of the heads off.
01 is the Cylindrical Lens (Render Settings> Effects
11 is a camera set to Spherical>Full Frame and to the angles needed for that tan = 540/2069 cm. Here as + and - hence the 540 (up and down). This will result in an angle of 14.6276º
Let me know if that fits your needs or if the set up needs to be different.
If I put this on my circular canvas (which is what will be done by a series of projectors in the real world), when the particles reach the “edge” of the unwrapped canvas, they will be clipped.
So what I’m trying to do is to create my particle animation in a curve, so that it can become an “infinite texture”. But then I need to render it flattened, and it will then be “re-wrapped” once it is played in the real world setup.
Does that make sense?
PS: I really like the scenes you shared. However my trigonometry is too limited to understand your math :(
But, maybe this is in fact the solution, but I am confused about why the figures appear so squeezed?
Please reload the scene files, I have adjusted the cylinder to match exactly your texture resolution. Including the Spherical field of view. (Before that I adjusted only for the given cylinder)
You will also find, if you press the play button, that I have had animation in it. The comparison between the Cylindrical Lens and the Spherical Camera is as said before.
While I was checking everything, your cylinder is not along with your footage ration, if I assume a square pixel. If the hight is fixed, then the diameter should be 2,802.825cm.
If the diameter is correct, then the height should be 1591.019cm. Perhaps check this with a texture that is 13K*1080, perhaps with circles on it, so the circles indicate a correct ratio.
If you take a look at file Cv2_r21_drs_19_REcc_01.c4d or …11.c4d, while in play mode, the scene is rotating. Render out one or the other and map the footage to your model. It should be without seem.
The edge to edge problematic will show up with glow and other Post-Render Effects.
In order to make this working, go to the render settings> X-Particles and switch off the High Q Render option.
I have set up both scenes with a super simple X-Particles, but I use the Sweep to get geometry here. This works in all cases.
I have checked the rendering with a 10% the render, I think the seam is not visible. Please check with a full-size render.
However, the render shows always two emitters. My impression is that 180º view (Cylinder Lens as well as Spherical Camera) will work at this showing one emitter, but also a seam.
I have no idea why it shows two Emitter!
Sassi, just a question about your REcc_03 file.
How did you determine the correct size for the spline you used to guide the particles?
Was it using your camera tool? I’m curious to be able to recreate this myself another time.
I have no idea why the emitter shows up twice, as mentioned before.
It does so even if cached, High Q is off, etc.: No idea.
This needs to be discussed with the support. https://www.maxon.net/en/support-center
Is the full projection circle at all, or is any audience only able to see a portion of it?
I see…Given that is the case, would you recommend another approach to get to the same result? i.e particle based solution to create lines that endlessly loop?
