OTOY Forums

Hi,

I have a test scene I've use to test composited objects and shadows of those objects onto a background. It works with the standard renderer, but not with Octane.

I used a background object to load an image of the street as a texture, then put a figure in and a plane. I copied the background texture object to the plane and set to frontal projection. Then I added a compositing tag and set the compositing background property.

With a light in the standard renderer, I get shadows and a properly composited scene.

If I then change the renderer to Octane and convert the materials, I just get a plane that doesn't show any shadows and doesn't composite.

Any idea what I'm doing wrong here?

I've uploaded the scene files for the standard and octane renderers separately, plus the street scene jpg for the background texture.

Cheers,
Kaleel

Hi Kaleel,

Here is your file properly set up for Octane.

Good luck!

Thanks Jayroth2020 so much for taking the time with that.

I've downloaded it and, while the compositing now works, I still don't get any shadows unfortunately.

Maybe it's something to do with the way I have things set up in the Octane render settings, or the normal render settings? I've read something about layers, multiple passes and beauty passes and so on, but I don't really understand it and don't know whether they are relevant.

FYI I'm running Octane X PR 1 plugin for C4D on a Macbook Pro.

Cheers,
Kaleel

Hi Kaleel,

believe it or not, there is a shadow there. Remember, Octane is mimicing real lighting scenarios, which standard render does not.

If you have a situation like this, where you do not notice much of a shadow, if any, there is usually one culprit: the default environment color. In your scene, the near white value of the environment color is effectively filling in the shadow.

Try this: change your environment color to H:205, S:26 V:73

This creates a pale blue/cyan color of low saturation and towards the brighter end of the value range. It will produce a really nice result in your scene (for starters) and give you the shadow you are looking for.

Even better, try adding in an Octane daylight. It matches the colors in your scene more closely. To take it even further, change your area light to a sphere and set your light falloff for Inverse Square.

Oh, and disable your original light -- something I neglected to do in the file I included.

I would also enable "Use primitives" on the area light, and enable "AI light" in your kernels panel. This will give you a fast, less noisy result, as it leverages the Spectron tech from a release or two ago. Play with your sphere size and light brightness to dial in the look of your shadow.

Thanks again for replying. Ok, I had a look at the image at the end of your last post and I can’t match that with the modified scene unfortunately. Mine has no shadow that I can see.

I’ve done all the things you suggested and managed to get a subtle shadow, but whatever I do, I can’t make it any stronger. This is what I get after those changes:



I’ve uploaded this modified project.

Cheers,
Kaleel

Hi Kaleel,

If you want a strong shadow, you can start by disabling the Octane sky object and changing the remaining light to a circle instead of a sphere. That will give you a more defined shadow, and remove the fill lighting from the areas in shadow. Doing so will look less natural, but it will get you started.

jayroth2020 wrote:Hi Kaleel,

believe it or not, there is a shadow there. Remember, Octane is mimicing real lighting scenarios, which standard render does not.

If you have a situation like this, where you do not notice much of a shadow, if any, there is usually one culprit: the default environment color. In your scene, the near white value of the environment color is effectively filling in the shadow.

Try this: change your environment color to H:205, S:26 V:73

This creates a pale blue/cyan color of low saturation and towards the brighter end of the value range. It will produce a really nice result in your scene (for starters) and give you the shadow you are looking for.

Even better, try adding in an Octane daylight. It matches the colors in your scene more closely. To take it even further, change your area light to a sphere and set your light falloff for Inverse Square.

Oh, and disable your original light -- something I neglected to do in the file I included.

I would also enable "Use primitives" on the area light, and enable "AI light" in your kernels panel. This will give you a fast, less noisy result, as it leverages the Spectron tech from a release or two ago. Play with your sphere size and light brightness to dial in the look of your shadow.

Resolved_Street_Scene.png

Hi Jay, does AI-Light work as well as on Octane 4.05? I have enabled it, but haven`t tested it properly..

Best

jayroth2020 wrote:Hi Kaleel,

If you want a strong shadow, you can start by disabling the Octane sky object and changing the remaining light to a circle instead of a sphere. That will give you a more defined shadow, and remove the fill lighting from the areas in shadow. Doing so will look less natural, but it will get you started.

Thanks. I tried those but unfortunately I can't get the shadow any stronger. I even tried a spot light, which did give more of a defined shadow, but it was definitely not a very dark shadow. Changing the density of the shadow didn't make any difference either. Could this be an issue with Octane X PR1 behaving differently to the usual Octane? I just can't get strong shadows whatever I do.

Cheers,
Kaleel

Hi Kaleel,

You need to set your environment color to black. Live Viewer > Octane Settings > Settings > Env > Default Environment color

That will get your shadows black

Unfortunately I'm totally baffled by this. I set the environment to black, which did change things, but I still can't get a dark shadow. And more bizarrely, the shadow is actually hollow!



Maybe I've accidentally changed a setting somewhere, because if I switch the light to a spot light, it comes out completely opposite to what I'd expect!



It's like the lights are outputting negative light and where the shadow should be is actually lighter.