Glow me, C4D!

D

djembeplay

Well-known member
Haha... contrary to what my title might imply, I'm really loving C4D... On the other hand, the title might imply that I reaaaallly love C4D... heh, anyways...

I just spent somewhere around 4 hours trying to solve this little issue. I also ran into it before and put some time into trying to solve it, obviously to no avail.

I want to have a glowing object inside of a glass sphere... and glass, naturally, has refraction... as does my glass sphere. The thing is, nothing seems to glow in reflections or through transparency or refraction. I tried tagging my objects, tried a bunch of render settings, etc... nothing.

So, ya... you would think I could just run a multi-pass render to isolate the glow and composite it later. The thing is, though, that once I remove the object that is inhibiting the glow (the glass sphere), I also in turn remove the refraction... So... It doesn't match up at all obviously.

I could crop the 'glow' layer and manually match it up with the actual object, but it would only be flush for one frame, then I would need to re-shape it again frame after tedious frame (b/c as you move, a refracted object's appearance behaves much differently... like a refracted object would/should).

Truly, the best solution is to figure out how to just get C4D to render it from the start...

Thanks for any help anyone can provide.
 
C4D doesn't render glows behind transparent object or trough reflecting one's

One solution is (perhaps) to uncheck "seen by camera" to a compositing tag applied to the sphere ball render the object (but i dont know if it would render the refraction, try it)
and create the glow in After Effect or motion or wathever and recomposite withe render of the glass.

Else you might try to render the scene with the glass bowl but without reflection and specular and with full transparency to get the object only…

They are "dirty" tricks but they might work!
 
Just do it in AE. Assign a external compositing tag to the object, export an AEC, then create your glow and parent it to the null from the AEC and use multipass to have the refraction, etc broken out on their passes to composite the glow under it.
 
Awesome, thanks guys... I didn't know you could render an object seperately but still maintain it's refraction aspect caused by another object... I'll give these options a try and report back.

It will be a little bit b/c I'm rendering an image that will take 10+ hours to finish! I completely maxxed my system out on this one... Needless to say I'll need to clean-up a bit if I actually want to animate it. I think it's the combination of having alot of displacement textures and having hundreds of light shafts...

K, thanks again.
 
Ok, I tagged my object w/ external compositing, then exported an AEC and opened the project file in after effects. The object doesn't seem to be seperated from the image. If I solo the object, all I get is a black screen... There seems to be an outline box associated with the object and a light. The corner of the outline box is touching the object, but is not around the object...

Eh, hard to explain. I'll upload my project file in a little bit if anyone is interested in taking a look...
 
Hmm... I was thinking that the glass sphere glitches were probobly an AA issue as I've had that happen before... but I just upped the AA rate last time... I usually do use animation, but I didn't know that switching it to Sinc would make a difference. So I may be able to just switch it without upping the AA rate? I'm not sure what effect changing the filter types has...

So I'm still confused about the DOF glitches... It looks like it has something to do with my displacement mapping on the stelactites/stelagmites... If I turn off 'sub-polygon displacement' it seems to go away, at least from my brief test. But, regardless, I should be able to use sub-polygon displacement w/o this happening...

Someone mentioned that I can just apply a DOF in AE somehow... really??

Thanks alot for the help.
 
Ah, ok, I figured out how to extract a depth mask via multi-pass render from C4D... So now I have my image and my depth mask open in AE, but I don't see how to actually apply the mask to the image as a DOF mask...
 
Ok... I just found a tutorial someone posted on how to use a DOF matte in AE... Lol, the results look horrible compared to the C4D DOF.

The method he/I was using is to apply a compound blur to the image and set the blur image to the DOF mask... I mean, ya, I lowered the blur and raised the contrast of the DOF mask, but it only made small differences... It certainly never came close to the quality of the C4D DOF. There was always a slight blur around the object I had in complete focus as well (the sphere)...

Am I missing something? Is there another way to do this in AE that I don't know about?
 
It's the displacement conflicting with the DOF in C4D for some reason... I tried changing a bunch of settings... the only thing that works is to reduce my displacement to basically nothing... which isn't the look I want...
 
Doing DOF in AE is the way to go. Easier to control, faster to render, and you avoid the transparency problems (along with all the other DOF issues with C4D due to it being a post effect).

Remember, in the end the goal is to trick the eye, you don't need to do it technically perfect, just artistically.
 
Really? Interesting... It's funny that the C4D depth matte is more accurate than the DOF effect... It actually seems like it would be more work to make the DOF effect not as accurate as the depth matte... I wonder why they don't just use the same depth matte for their DOF effect... Idk, there might be some things here I don't understand though.

Anywho, so I'll have to play with the AE DOF a bit more. I've found a couple tutorials, both using different methods... Neither have given great results. Do you know of any other method besides using the compound blur & using the depth matte as the blur channel? That was the best of the two methods I found... the other one was this, but it seemed worse:

http://www.3dartisan.net/jeb/tutorials/fake%20DOF/fake_DOF.html
 
Success! I discovered the lens blur in AE... that's capable of a verrrry nice DOF blur. I rendered a couple photos - one with AE DOF, the other with C4D DOF... I tweaked the AE DOF to mimick the C4D DOF. There are some fine differences just by the nature of the beast, but they are preeettty close... check it out:

AE DOF:

AEDOF.png



C4D DOF:

C4DDOF.png
 
Very cool. Oneinfiniteloop is the C4D and/with AE high mick muck 'round these parts. His advice is always spot on.

Anything you can do not in your 3D program, save it for post. Not only do you speed up your workflow, but you have the options of changing things on the fly, without having to re-render anything.

If the man says multipass, multipass it should be.


And great work, by the way.



ps, out of curiosity, what was the render time difference between all C4D and C4D and AE?
 
In AE you can use the lens blur plug-in for DOF, better than compound blur because it takes into account highlights, aperture size, etc. The best way to go would be to get Frischluft Lenscare, it's one of my favorite post DOF plugs. Also, to get better results, render out your depth map at double resolution then scale down in AE. This will help with the banding and such.

Lenscare: http://www.frischluft.com/lenscare/lenscare.php

Now, you need to render out a multipass image so that you can get your DOF behind the glass.
 
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