Stage Lights (spotlights)

[thirteencreates]

I am having to design stages and need to include spotlights in my scenes. I'm wanting to know if there is an easier way to achieve what I am trying to accomplish. The only way I know how to make a spotlight with a light beam is by making a cone, applying a volume material to it, and attaching a light to it. It makes my preview scenes awfully dark and hurts my render times.

[TomG]

You could just set the light to have directionality, and apply a global volume material. Of course anything with volumetrics takes longer than without volumetrics, as you are asking the render engine to do significantly more calculations. Be sure to have single bounce only enabled.

[BigAl3D]

Your first question is what is the end product? A visualization to sell a design? A photorealistic render or is it an animation?

[c4d019]

You could just set the light to have directionality, and apply a global volume material. Of course anything with volumetrics takes longer than without volumetrics, as you are asking the render engine to do significantly more calculations. Be sure to have single bounce only enabled.

I'm not quite sure I understand, do you apply a volume material to the actual light in order for it to emit a volumetric effect?

[Cinemike]

A global volume material would go here:

[TomG]

See above post :) Just like the real world, volumetrics is not a property of the light in Corona, but a property of the medium it passes through. So lights do not have any volumetric settings at all - those are either assigned to the whole scene (Global, as above), or assigned to particular geometric objects (e.g. a pool of water, a patch of fog, etc.)

[thirteencreates]

Thanks for the insight! Glad to know I am doing it correctly. Just feels like too much work to be honest. I can't see the light when I set directionality. Would be nice to see Corona introduce a spotlight like the native c4d one.

[TomG]

Just in case you don't know, you can use native Cinema 4D spotlights, and they will work with Corona Volumetric materials.

[thirteencreates]

You can't see the spotlight unless a Volumetric material is applied to it right? The native spotlights have the option to automatically add volume. It would not render in Corona unless I had the volumetric material applied. Is this correct? Or am I missing a step?

[TomG]

The volumetric settings in the C4D spotlight don't work. You still treat this as the real world, just like with a Corona light, you set up the volumetric material - and then Corona lights and C4D spotlights will show up in the volumetric material. Nothing will show up using the native C4D spotlight volumetrics, so leave them disabled. Not sure what you mean about "not seeing the C4D spotlight without volumetrics being enabled" - you will see the spotlight, as in the source, and the light it casts into the scene, but you won't see the volumetrics without volumetric media that the light is passing through.

[c4d019]

Once you figure it out you'll probably end up disabling it anyway due to long render times and excessive grain. I know would be so nice to have quick and easy volumetric lights within corona but doesn't seem to be a priority for the team.

Anyway I found a quick workaround, assign your desired volumetric lights to a layer within c4d, then render out your final scene in corona and save image. Then solo the lights to which you assigned a layer, switch renderer back to standard and watch and marvel at beautiful and lightning fast volume effect coming from your lights. Then save image with alpha channel and composite on top of corona render.

Seems kind of counter intuitive i know but it's fast and at least you have control over the colour and intensity of the volumetric effect within image editing software.

Good luck.

[houska]

It is possible to fake the effect with a cone volume with attached Volume material, but it's very finnicky to setup the correct values for the Volume material. I'm sure it would be possible to create a C4D plugin that does this.

[thirteencreates]

Thanks for the further insight. My issue was not being able to see the beam without a volumetric material applied. I have been using the cone trick to achieve the beam look I want. I have found it is faster to just make big cube with a volumetric material applied to it and place all spotlights in that but my overhead light will light up the cube. Is there away to to exclude certain lights on the volume material?

Thanks for your tip! @c4d019. That thought totally slipped my mind and will help speed up the process to help with deadlines. The scene just gets so heavy on RAM with all that volume and spotlights that is hard to maneuver or notice fast changes in the VFB.

[TomG]

Sorry, no way to exclude lights from the volumetric media - again this ties to Corona being like the real world, if a room is full of smoke, any lights shining through that smoke will bounce around due to those particles, not just a few of the lights. The only way would be doing separate renders and compositing in post.

[Ealexander]

I am a huge fan of Corona.  I love it and use it everyday for most of my work.  I have told everyone who will listen to buy this render engine.  I've taught classes on it, I've written for their blog.  I am a fan.

That said - I have found volumetric stage lights to be a real struggle with Corona and have gone other routes to achieve this - this is after extensive testing and trial and error.  I mostly render concerts and events, so beams of light are a huge part of my workflow.  I ran into the same issues that you have raised and was never able to get an acceptable workflow going that I like.

Now, I do the base render in Corona, and I put the Corona lights exactly where I want them - usually making them visible and adding bloom and glare.  This gives me the source light in the render and it lights the objects on stage in the correct way.  I then switch over to Redshift and put a black texture over everything.  I match up the redshift lights to the Corona lights (thank you PSR Reset) - and with RS I can dial in the beams on each individual light to taste.  I then comp it all together in Photoshop.  Worth noting - 99.9% of my work is stills, not animation, but you could do the same process for animation if needed.

I have also had great success just doing the beam overlays in Photoshop directly.  It sounds like a lot of work, but I've written some pretty nice light cues in PS.  I've used Video Co-pilots Optical Flares to create a series of flares, beams, and cones on a matte black background that I can screen into my layers in Photoshop and set up the lighting look manually.  I prefer to render them out now, but I use both methods depending on the job and time of turnaround.

You can absolutely do this with the native C4D volumetric light system, but I have found other render engines to be faster and handle the lighting better.  If you look at my website, you can see examples of both of these techniques in almost every performance render.  Good luck!

Absolutely no disrespect meant to the Corona devs - like I said, I love this engine so much, but I don't think any one tool can do it all, even if it's your favorite one.

e.