Lighting and shading C4d

[HandsomeRob]

Hey again.

I wanted to compare a pretty simple scene that I have made in the past and rendered with Maxwell, but I ran in to problems straight away

I want to make textured lights, not just a plain "softbox". Let's say I want a light with a gradient from black to white to make a nice reflection on my can, how do I do that? I've been fidelling around with this for hours now, and I cant get it to work.

The other thing that i struggle with is the shading. If I want to add another specular layer to the metal on the can that is a little bit more blurry, how do I do that? Do I need to create a mix-material?

Please take a look at the image if that helps to understand.

https://dl.dropboxusercontent.com/u/538 ... shot.3.jpg

PS. I can't get my head around the shading/ material editor. I think it's confusing that you see all the channels (reflection, diffuse, index and so on)all the time eventhough you can't use them with certain materials. I think Maxwell's approach is better with a separate interface instead of cinemas native material editor...but that's just me

Thanks,
Roger

[FooZe]

Hi Rob,

You are on the right track with a texture emission.
Make sure you use octanes texture emission for the emission pin:

And then use an octane imagetexture for the "efficiency or texture" input of the texture emission:

Load a jpg/png/whatever gradient image into the imagetexture:

It should look something like this (quick test of concept):

Playing with the index of the glossy material of the can should allow you some tweaking of the falloff too.

For additional layers, yes you will need a mix material. You can mix any two materials with a mix material, you can control the mix amount with any of the normal textures (image file, procedural, dirt, falloff etc), or just a uniform value (floattexture).

You might find it useful to try to familiarise yourself with the material system using the standalone, then transfer that to c4d. Try these tutorials: http://render.otoy.com/forum/viewforum.php?f=51
(or any others you find browsing the forum/web).

Thanks
Chris.

[HandsomeRob]

Thanks Chris.

I tried your approach and it worked pretty good. It worked even better when I loaded the same gradient in the diffuse-channel as well, so that's good

I will look in to some more tutorials and see if that helps me in my struggle.

I ran in to another problem now...I have created some small drops of water on the can, but they just render black. I have tried a boolean with and without cap and with the drops penetrating the can...but it's not working out.

Screenshot of render:
https://dl.dropboxusercontent.com/u/538 ... shot.4.jpg

The Cinema 4D file with a gradient texture:
https://dl.dropboxusercontent.com/u/538 ... _drops.zip

If anyone do have some time I would be greatful

Thanks,
Roger

[ChrisVis]

Thanks Chris.

I tried your approach and it worked pretty good. It worked even better when I loaded the same gradient in the diffuse-channel as well, so that's good

I will look in to some more tutorials and see if that helps me in my struggle.

I ran in to another problem now...I have created some small drops of water on the can, but they just render black. I have tried a boolean with and without cap and with the drops penetrating the can...but it's not working out.

Screenshot of render:
https://dl.dropboxusercontent.com/u/538 ... shot.4.jpg

The Cinema 4D file with a gradient texture:
https://dl.dropboxusercontent.com/u/538 ... _drops.zip

If anyone do have some time I would be greatful

Thanks,
Roger

Hi HandsomeRob,

I just tried out your scene.
You just have to increase glossydepth to min of 3, better 4 in the directlighting kernel...
Then it works, but you need some more lighting to get the drops seen as real water, because they just reflect the black cylinder you are trying to use as a studio, expecially on the right side, where no lightsource is present.


I also would use another material for the can... there are some aluminium mats on the LiveDB.

Did you try lighting with texture environment and a studio HDR?

[ChrisVis]

Hi HandsomeRob,

I did some more playing with your scene and ended up with this.

Not the way you wanted to do it, but I used several Octane Lights instead of the gradient texture light and placed them around the can.
Also closed the Studio Cylinder with a top and a bottom plane, so there is no light coming in from outside.
The left and the right light has visibility on (opacity slider to 1), so you see some more nice reflections, like from a large kinoflo.

The Backlight and Frontlight are invisible and just light up the scene.

The bottom and top light does emitt very little light but is also visible and is seen as light reflection in top and bottom of the can.
I also used a nice basic aluminium material form the LiveDB, with this one you automatically get these nice gradients, so no need for gradient lights.
Maybe it is a bit different from what you wanted to achieve, but you can play with the lights, turn off the right light for example and you will get more of the result you have been looking for. Also play with the watts of the light or the distance and placement of the lights to get different results.

Here is a CloseUp I renderd out.

And finally the edited scene.

octane_dropsEditChrisVis.zip

(4.02 MiB) Downloaded 356 times

I had some strange issues with your camera. Which version of C4D did you use to generate the scene? When adding another cam and octane is already active, it sometimes was not possible to switch between cameras. Don`t know why.
I also tried to render out the can at your high resolution specs... turned out that about 600 samples are enough... cooked about 8 min with 7 GPUs here and made a 220MB TIFF file

Btw, how did you make the drops? Inside C4D? I would like to see them moving down the can and do some animation with it... that would be quite fun.

Greetings,
ChrisVis

[HandsomeRob]

Wow, thanks ChrisVis.

It didn't cross my mind that the kernel-settings could be the problem. As you where saying it helped a whole lot to bump up the glossydepth, but it was even better when i changed it to the "pmc" kernel. Then it starts to act as it's "supposed to" in real life, because even if you have a black studio the drops shouln't reflect black, it should just be transparent/refractive where the fresnel isn't taking effect.

Concerning the aluminium I would say that it creates hard reflections, but that's just me
http://commons.wikimedia.org/wiki/File: ... Italia.jpg

I have created the drops in cinema 4D. Painting out small sphere's with a plugin that's called paint on surface and then grouped them inside a meta-ball. It's not looking fantastic, but OK I guess I have stared watching a tutorial from Digital Tutors on how you create drops in Realflow...looks pretty neat and alot easier to animate

Since I only use the demo at the moment it is very interesting to hear that it renders that fast in high res. But I'm only at one GTX 670 so I guess that would take me about an hour, and probobly more if I want to use PMC kernel?

Thanks, this helped me alot

Screenshot of render with pmc and two gradient lights.
https://dl.dropboxusercontent.com/u/538 ... shot.5.jpg

[ChrisVis]

Hi HandsomeRob,

did some more playing with the can.
And yes, Aluminium isn`t that rough in the reflections, so I tweaked a little bit.
I only got rid of the black reflections in the bubbles by activating fake shadows. (especially with the red aluminium. With grey aluminium it seems to be easier.)

Now rendered with pathtracing at your full resolution settings (5313x7086) with 300 Samples, downresized to 3000x4000. Cooked about 15min with 7 GPUs.

Not perfect yet with the reflections, but I think a good startin point. The Logo isn`t placed 100% perfect, because I don`t know the exact parameters of the can. Also the bubbles seem to get eaten up by the white logo if fake shadows is enabled.

Greetings,
ChrisVis

[ChrisVis]

Hi all,

here is the project file for the coca cola can. The logo is inserted as PSD (just grabed it from a free logo source side http://www.seeklogo.com, and converted to PSD), it can be edited or replaced easily, but would need some more work for perfect fitting. You may have to reload it because of different texture path.
A nice and easy studio scene setup, especially for greenscreen, to get some great results.

octane_dropsCocaCola.zip

(4.11 MiB) Downloaded 348 times

Thank you HandsomeRob again for sharing the original project file, learned something, too!

That leads me to the idea how we all here could learn a lot from each other:
How about a subforum, maybe in the art work forum, for especially sharing scene files to share some skills in terms of different aspects... like studio work, interiors, exteriors, lighting etc.?
Simple scenes, that can be exchanged easily.
Maybe only self modeled stuff or at least with named model and texture sources to avoid copyright issues.

What do you think Octane Team... would this be possible?
Could help a lot...

Cheers,
ChrisVis