Author Topic: Request for checkboxes for material slots in RaySwitchMtl  (Read 5466 times)

2014-07-16, 18:17:57

pokoy

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It would be good to have checkboxes next to the materials used in the RaySwitchMtl for quickly enabling/disabling materials. Right now you have to copy a material to another slot, clear it in the RaySwitchMtl and paste it back when all you want is just to disable it. It's a bit tedious atm, a checkbox would save us some clicks.

Same goes for both bitmap slots in the ShadowCatcherMtl (didn't want to create a separate thread for that).

2014-07-16, 18:52:14
Reply #1

Ludvik Koutny

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They actually were there, but were removed to make RaySwitchers clean and not confusing. It may now be little more difficult to swap things around, but:

A, RaySwitcher is not something you usually use many times day

B, When you use RaySwitcher, you do so when you exactly know what you are doing and what you are after, so you do not do much experimentation.

2014-07-17, 09:32:32
Reply #2

pokoy

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It may have been meant to simplify things but it's actually limiting.

I guess I'll have to accept your point of view but I'd be happy if you had a second thought on this.


2014-07-17, 10:07:34
Reply #3

Ludvik Koutny

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It's not my call. I was originally against (there were actually two sets of checkboxes and it made rayswitchers quite confusing), but you are first person in a long time to use rayswitcher, so if you believe they would simplify your workflow, then i'll ask Keymaster about adding them ;)

2014-07-17, 10:32:25
Reply #4

pokoy

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Ok, thanks.
It's especially useful for any kind of rendering against a backplate. I usually take a ray switcher with a shadow catcher for the direct visibility, a camera mapped material for the reflected visibility and whatever helps to make it look good. The checkboxes are very useful for quick testing or rendering different versions for the comp without having to clutter up your matedit with all the materials that you need in the ray switcher.

I guess all people rendering for comp will find it useful at some point, so thanks for considering.

2014-07-17, 11:08:55
Reply #5

Ludvik Koutny

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I usually take a ray switcher with a shadow catcher for the direct visibility, a camera mapped material for the reflected visibility and whatever helps to make it look good.

Why would you do that O_o !!!?

ShadowCatcher automatically camera projects the backplate, and it does so in a correct manner, so that in reflections, you are reflecting correct unmodified lighting information of the original backplate but occlusion from integrated CG objects.

ShadowCatcher does not need rayswitcher to provide good results, and i can not possibly imagine what visual benefit would it ever provide.

2014-07-17, 11:28:54
Reply #6

pokoy

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Well, that was exactly one of my problems yesterday, and I had to use ray switcher to avoid bright fringes on some of my reflective objects, regardless of how correct the current solution is.

I tend to rather set up all ray contributions by myself, that way I know what really happens. If you stick to the preset solution in the shadow catcher you might hit a limit somewhere. There's just no valid replacement for flexibility, and as far as I have learned this applies to any renderer ;)

I haven't tested but I'm pretty sure one very important thing from a common vfx workflow is not covered by the 'automatic' method in ray switcher. Sometimes you have to camera map (that's why camera map per pixel is very important, see my thread about the crash with A7) an image onto a groundplane or geometry and render the hero object with motion blur and make sure the reflections are motion blurred correctly. I suppose that the current mapping will move with your main render camera - but what you need is that it 'sticks' to the groundplane, so you're automatically forced to built a ray switcher setup to get around it. The automatic solution might work for one certain case, but some workflows require a manual solution that no one had in mind when a feature was designed.

2014-07-17, 11:48:49
Reply #7

Ludvik Koutny

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Could you post a screenshot of that fringe problem, so i can better understand? In A7, theres an energy conservation mode, that actually clamps result of reflection + diffuse when it exceeds 1, while other renderers balance the reflection vs diffuse scale uniformly by scaling down diffuse as soon as reflection starts to appear and vice versa. New energy conservation is available in daily builds, while Alpha V7 still uses the old one. My point is that old energy conservation produces unnaturally strong reflections at grazing angles, so that could be at least a part of your problem.

Other part of the problem could be tone mapping. I found that most of the backplates are at least slightly tone mapped by the camera, while HDRI maps are not (they must not be to work correctly. And when i was doing my Mercedes Benz renders, i found out that one of the biggest mistakes i did was i kept my car linear, while backplate had some slight tone mapping, so i had strong reflections around the edges of my cars and it did not fit the backplate. So it may be a good idea to set highlight compression to at least 2. And of course, backplate plugged in the shadow catcher and direct visibility environment override should be plugged in through the CoronaMapOutput node, so that it is not affected by color mapping, including highlight compression :)

As for the other note about motion blur:

1, set ShadowCatcher projection mode to Do Not Alter, this will make SC use input UV coordinates.

2, plug your backplate through Camera Map Per Pixel node into backplate slot

3, chose static camera as Camera Map Per Pixel projection camera

4, use different camera as the moving one

The thing with Corona is that fakes are often penalized by performance drops.

2014-07-17, 12:09:43
Reply #8

pokoy

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About the fringe - you're right, that could indeed be the reason, though some of the objects were definitely in shadowed areas.

Tone mapping - will keep this in mind, but this is not what I'm seeing it seems. Sorry, I can't post any screengrabs or scnene parts and I am confident I am not breaking any internal rules of what Corons expects to render correctly.

Motion blur - exactly what I'd do, only that I wasn't aware of the 'Do not alter' option. Good to know. Though the crash with camera map per pixel needs to fixed for this to work ;) I totally understand why you suggest that in order to avoid performance drops or issues with physical behavior, though.

Hmm. How do I get access to the daily builds? It seems it's worth going with them for the energy conservation fix alone.

2014-07-17, 12:21:03
Reply #9

Ludvik Koutny

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About the fringe - you're right, that could indeed be the reason, though some of the objects were definitely in shadowed areas.

Tone mapping - will keep this in mind, but this is not what I'm seeing it seems. Sorry, I can't post any screengrabs or scnene parts and I am confident I am not breaking any internal rules of what Corons expects to render correctly.

Motion blur - exactly what I'd do, only that I wasn't aware of the 'Do not alter' option. Good to know. Though the crash with camera map per pixel needs to fixed for this to work ;) I totally understand why you suggest that in order to avoid performance drops or issues with physical behavior, though.

Hmm. How do I get access to the daily builds? It seems it's worth going with them for the energy conservation fix alone.

Crash with camera map per pixel will definitely have to be fixed. Nothing in Corona should ever crash, let alone such basic feature as camera map.

Rayswitcher is quite untested territory so far, so Keymaster is not yet completely sure nothing internally breaks when using it in various crazy situations. But you are welcome to put it through stress test, so he can make it as bulletproof as possible.

And regarding daily build access, just go here: https://forum.corona-renderer.com/index.php/topic,776.0.html

Read the rules in first post, grab the appropriate daily build from dropbox, run it, paste request code as a reply into that thread with some of your Corona works attached. If you do not have anything to show, then PM me with your request code ;)

2014-07-17, 14:42:14
Reply #10

pokoy

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2014-10-30, 00:18:44
Reply #11

Ondra

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I've decided not to add the checkboxes... it would complicate the dialog which may be already confusing
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2014-10-30, 12:00:41
Reply #12

pokoy

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Oh well, it's your decision in the end. However, anyone using the switcher will probably know enough about what it's good for to figure out what a simple checkbox means ;)
I'm using it for quick checks, it just helps to have a checkbox instead of having to swap materials and clutter the material editor.

But we had our discussion on this already and I didn't convince you so will have to accept that.