Unable to project Gradient through camera

[cashley]

Maybe I'm missing something, but I cannot figure out a way to project a gradient through the camera onto a background. From what I can tell, only image textures have the ability to use a projection node. Any help would be appreciated. Again, I'm just trying to project a gradient through the camera.

Thanks,

-chad

[aoktar]

Do you want to map it across camera view direction, from black to white? As distance to camera?
Gradient is not generator, a mapper. Try that with a sine/triangle wave node connected to gradient. Connect transform/projection to wave.

[cashley]

Sorry I probably wasn't being clear.

I'm currently using an image texture as my background and it is also being projected onto the floor (see attached image) using the matte shadow technique I've seen posted up here a few times. My issue is that I would rather not use an image texture but use an actual gradient. BUT, the gradient lacks any sort of projection control. Any help is appreciated.

[aoktar]

I described that's possible but complex. Nevermind that. Go with background object and put a c4d materials with a c4d gradient. Activate alpha.

[cashley]

AWESOME! Thank you SO MUCH!

[cashley]

I may have spoke too soon. Looks like I still cannot get my diffuse gradient to be mapped to "Frontal" while it's alpha is set to UV space. In the attached image you can see the orange gradient that is mapped to my background object. I have a ground plane that has that same shader applied. You can see in my ground that the gradient is not mapping to "frontal".

Can you explain your more involved workflow for projecting gradients through the camera?

thanks!

[aoktar]

hide all objects and check background result what you see? It's a 2d effect not 3d so not possible that don't to be "frontal". You are mixing gray of plane with background pixels.

[cashley]

Here is just the ground plane. It has the same c4d shader applied as my background object. There is also a circular gradient mapped to the plane's alpha so that it falls off in opacity from the center.

[aoktar]

Don't go this way, i think you assume that will be frontal when you put it 3d object. Background object is 2d effect, plane is 3d. So of course it's frontal on background, because it calculate shader on screen space. It's uv mapped on 3d object.
C4D shaders are converted images and is applied by uv mapping. Just use Octane material->Matte option here. It's under common tab.

[cashley]

Thanks for the quick reply, however, the "matte" function gives me unwanted results. The ground no longer casts shadows or GI. See attached image around the contact point of the tires. Also, the shadows feel like they have no color.