Camera projection problem

[imago10]

Hello!

I have simple geometry with Camera Projection on it. And in C4D everything looks fine but in Octane Live Viewer/Picture viewer it looks very distorted. I try to subdivide geometry - this helps a little. But it's possible to have Camera Projection texture like in C4D on small subdiv geometry? Generating UVW doesn't help. Any tips?

Thanks,
Lukas

[imago10]

Ok I can't find solution. I think it's Cinema - Octane. Bug.

[niestudio]

can you post your scene?

[aoktar]

Ok I can't find solution. I think it's Cinema - Octane. Bug.

Bug hmm. Not..! It's doing a cameramapping to uv conversion to simulate that. You need a better subdivision.

[imago10]

OK but in Cinema 4D everything looks fine. So Octane need high dense mesh for camera projection?

[aoktar]

OK but in Cinema 4D everything looks fine. So Octane need high dense mesh for camera projection?

I believe that I tried to describe technical background. You need a better subdivided surface due the approach. Try with a pure plane with more division.

[noisyboyuk]

I've just come here for the same reason. My image is zig-zagging when re-projected using "Camera Mapping" as the camera projection (and linking the camera which I wish to project from).

Out of curiosity, why would you need to have more subdivisions just to project a texture onto a plane? Is there a way to do it so you don't have to use a more dense mesh?

I recall using Perspective in the Octane project node about a year ago for a big VFX job and that worked out pretty well but now I'm trying to replicate the technique I am struggling. For some reason the image comes out scaled up pretty large and flipped over. It would be good if there were a preset in the projection node which sets it up for camera projection without having to dial in scaling values etc.

Thanks

[noisyboyuk]

Just a follow up.

I managed to use the Perspective mode in Octane's projection node using my camera to project from which then let me use whatever subdivision level I wanted.

To do this I set it to Perspective, then the Position setting to World Space. Then I set the scale values to:

X = 1
Y = 0.56
Z = -4

CINEMA 4D_2018-10-20_22-21-22.png (6.23 KiB) Viewed 5138 times

I managed to find an old project I did where I had set up exactly this same set up but the issue which gets me close enough but I'm never going to remember those exact settings whenever I need to do a camera projection and it's a but inaccurate.

After reading the manual I saw that it takes the world space coordinates and divides the X and Y coordinates by the Z coordinate which I'll be honest I don't fully understand the reason for this. I'd love to hear why this particular setup is useful and why the x and y coordinates should be divided by z for projection.

Like I say, it would be enormously helpful to others I think if there was a different setting which is more similar to C4D's own Camera Mapping setting (which is useful as it has film back settings and pixel aspect ratio settings etc).

Thanks

[noisyboyuk]

Well I'm even more confused now after looking at the Camera Projection example scene. In the values are totally different. I can't seem to work out the precise formula to get the projection to work accurately every time without having to manually dial in scale values and eyeball it.

Any advice would be amazing

[aoktar]

Well I'm even more confused now after looking at the Camera Projection example scene. In the values are totally different. I can't seem to work out the precise formula to get the projection to work accurately every time without having to manually dial in scale values and eyeball it.

Any advice would be amazing

Test and compared the both of C4D's camera mapping and Octane's perspective projection methods. These values are giving exactly same outputs.