Ok.. one more - photographic studio/lightbox backgrounds & reflections?
Turner
Posts: 116
So, I'm doing some product renderings and in order to show some surface detail I want to emulate a modern lightbox or otherwise some type of studio background, like you might see on a car.
Sometimes it just looks like big white windows reflected across a surface, others it's more complicated.
Can anyone recommend any setups or products for this?
Also, I'm trying to figure out if there's a way to do this by using a background that reflects but does not render.
thanks,
Andrew
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I have a product called Fashion Studio.
http://www.daz3d.com/fashion-studio
It includes a full studio room, make-up room, camera, lenses, etc. Plus all types of studio lights, generator, umbrella, snoot, softbox, polystyrene panels and background rolls.
mac
HI Turner
Have you tried using shape lights,. like a plane
If you want to make a Lightbox,. or light array,.
You can jump into the vertex modeller and create one.
Make a vertex rectangle and extrude it into a Box,. with an open end,, make a vertex grid "plane" for the (diffuser) position the parts,. and name the parts, Select the Plane (which will be the light) and give it a separate shading domain. (so you can add a glow shader, and Anything glows lights)
Select your model in the assembly room, and go to Edit / Add new Anything glows light
set it up to use object glow, and add a shader (with a glow (value or colour)) to the light panel,
You could also use a hemi-sphere,. without a diffuser panel,. and simply have the whole thing use anything glows to emit light.
this image was done with two hemisphere's with Anything glows lights
I am currently working on a Carrara product that produces photographic studio type renders with a variety of lighting, backdrop and camera options. Regarding using the background for reflections only, try using an image in the Backdrop as this means that you don't see the Background in the render. A simple black or white Backdrop may give you what you want.
As Phil says about hiding the background, you can use an image in the scene backdrop or even a color or color gradient. The other option you have, which may give you more control in post production, is to render with an Alpha Channel. You can enable the option in the Render Room. The file format you save it to must support alphas.
that's wonderful news Philw
One of my first jobs in college was working in a commercial photo studio in NYC, so I can give you a little insight into how you can do this. With all due respect to the vendors, with a few basic principles under your belt you can duplicate what the studios do very easily.
First of all, it depends very much upon what product you are rendering. There is an art and a science to photographing products, and for different products there are different methods, rigs, and arrangements used to highlight that particular product. Lighting a gemstone is far different from lighting a Maserati.
Also, there are two basic purposes for the lighting setups in a studio: 1. Providing light, and 2. Providing something for the surface of the product to reflect. Which means your lighting setup might not provide light, it might just be a bright white (or other) object that will produce really cool highlight reflections in the surface.
But there is no "right" answer or arrangement or equipment, it depends upon the product and the purpose. As you will find out, photographers use all sorts of arrangements to get very specific "looks" in their photographs.
The first step I would recommend is to search the internet for photos of various photo studios, and look at what equipment they use for the different products. For examples, automobiles are generally photographed surrounded by huge softboxes, because their surfaces are very reflective and require lots of reflective highlights to look cool.
Once you have an arrangement and type of equipment figured out, there are many ways to duplicate them in Carrara (or whatever).
Personally, I very often use a very large flat plane with a very simple shader that only uses a single channel, the Glow channel. That will give you a glowing white object to reflect in the surface of the object you are rendering. However it doesn't provide any light. Very simple to do. Keep in mind that, depending on the product, you may or may not need a fancy lightbox. Maybe what you really need is just something to provide reflections, together with a simple lighting setup that also renders quickly.
If you also want light, it depends on what type of arrangement you want, as I mentioned before. If you want something that provides "soft" light (like a photographers "light box") you can use an object with Anything Glows applied. Or you can use one of the Shape Lights.
If you want a standard "strobe" light, then just use a spot light.
Again, there are many ways, and it really depends on what effect you want. I did a quick, 5 second web search and came up with this link that has some photos of various automobile photography studios to get you started.
http://www.core77.com/blog/photography/car_studio_photography_set-ups_21672.asp
Just to add something to Joe's good advice, if you turn on Indirect Lighting, a glowing object will emit light and can be used as a good softbox type light source. You will most likely need to use a multiplier to increase the glow to over 100% - try 1000% or more.
I tried a setup like this a couple of weeks back and it does work, but there is one factor I didn't expect. Using glow-channel only for light seems to give extremely-reduced specular effect from the highlight/shininess channels. This was too much of a downside for me, so while I still believe the power of the glow channel can be useful in GI, I also pair it with anything-glows real lighting as well. A little similar to how I treat hdri lighting, actually, now that I think of it.
I tried a setup like this a couple of weeks back and it does work, but there is one factor I didn't expect. Using glow-channel only for light seems to give extremely-reduced specular effect from the highlight/shininess channels. This was too much of a downside for me, so while I still believe the power of the glow channel can be useful in GI, I also pair it with anything-glows real lighting as well. A little similar to how I treat hdri lighting, actually, now that I think of it.
In real life, specular and reflection are the same thing. Specular is simply reflection from a light, and because lights are much brighter than their surroundings, shiny objects will sometimes have a specular highlight without having noticeable reflection (it is there, just at a low level). In Carrara, the two are handled completely separately, specular deals with "lights" and reflection deals with "other stuff" including glowing objects, so adding a low level of reflection will bring back your highlights where you need them when using glowing objects as lights.
Wow...okay, I know I'm gonna get severely trashed and called all kinds of names by some folks here for daring to challenge or correct what you say, but so be it...
Phil, I think your explanation is a bit, well.....let's just say you might want to re-word it to make it clearer....
In fact, specular is a TYPE of reflection, as is diffuse. Specular and diffuse describe different types of reflections. And the reasons there are those types of reflections is because the characteristics of the surface. Specular reflections occur off smooth surfaces, and diffuse reflections occur off rough surfaces. When you say "specular is simply reflection from a light", that's just not necessarily true. Specular is a reflection of ANY light rays (whether from a light source or from a bounced reflection off something else) off a SMOOTH SURFACE. It's the surface characteristics that describe specular, not whether it's a reflection from a light or not.
EVERYTHING WE SEE has reflection, or we wouldn't see it because light wouldn't bounce off it and into our eyes. EVERYTHING. And at one end of the scale of smoothness is a mirror, with a fully reflective surface, and at the other end of the scale is a super rough surface that only reflects a very soft, dispersed light. But it's all just a matter of degree of reflection.
One might even imagine a single "Reflection" slider for a surface shader that combines all of the reflection-related channels into one. With the slider at one end the surface is a mirror, and at the other end it's a very rough, diffuse surface. That's a gross over simplification, but hopefully it makes the point.
Now 3D software has to come up with some ways to separate that reflection into workable components. That's why we have separate color (which is diffuse) and highlight and shininess (which are specular) and reflection and SSS and translucency controls. It's ALL about reflection.
Anyway, let the trashing begin....
All very true, but just to warn the unwary....
If you go with reflections, there is a render time cost to be paid, and for many textures it should be blurred reflections that would be checked, and the render time for blurred reflections is so high as to make it almost an unusable function (this is something I wish the carrara programmers would address and correct to make it more useable).
Also I was reading that for many highlights we see, particularly on human skin for example, that a very high amount of the reflected light will be white, and I think the highlight/shininess function is set to address that, and if fine tuned can be pretty close to physically correct.
And I imagine lots of other people do this, but I pretty much always render with multipass on so I can examine the various passes used (render time is the same so why not?) and I've noticed there's a little amount of specularity generated in the Global illumination pass, and there can be a huge amount of specularity in the SSS pass depending on how it's set (from diffuse reflections mostly, I think).
All just food for thought to consider when deciding how to illuminate the scene :)
Jonstark wrote:
Oh I just started doing it a few weeks ago and then stopped as my hard drive was getting very confusing :) (I rendered them not imbedded)
No, I was using them for post work but my chief c and c'er didn't like my new "style.'
Which particular ones are you finding most useful?
thanks for your advice
PS I was using depth for haze, the uv one to get a little more illumination in corners that were too dark (set that layer to soft light from memory) but yyou need to put a diffuse pass over that layer and set it to colour to get your colours back). Someone has recommended the object index one as that isolates each object which coujld be very handy, and I was rendering out a shadow pass and blurrying it out to mimic soft shadows
Honestly, I have such extremely limited postwork skills I don't really have the expertise to use any of the multipass results for any postwork at all (which is I guess probably the reason most renderers do multipass, now that I think about it) :) Ever since Philw's tip about gamma correction to 2.2, I've restarted my quest to try to find a good SSS setting for skin, so while I multipass nearly all the different passes possible, I'm primarily looking at the SSS, Specular, Reflection, and GI passes, but I really just examine them and keep them around long enough to compare to a render with a slightly different setting, then I delete them. Still they do start to pile up in the rendering room for carrara if I'm not careful :)
Hi Jonstark
Thanks for replying :) The most useful tool for carrara post work is the clone tool to clean up poke through ;)
you probably know this but
when doing non -embedded mulitpass renders name the files first (there is a little check box thing in the render room that either allows you to select the default file name or a named file with directory. If you name the file before rendering it means you just have to close the multipass render windows and they will be named automatically without any other clicks from yourself, Saves a stack of time. I don't use embedded multipass because sometimes I get nothing embedded (user error obviously)
Wow...okay, I know I'm gonna get severely trashed and called all kinds of names by some folks here for daring to challenge or correct what you say, but so be it...
Phil, I think your explanation is a bit, well.....let's just say you might want to re-word it to make it clearer....
In fact, specular is a TYPE of reflection, as is diffuse. Specular and diffuse describe different types of reflections. And the reasons there are those types of reflections is because the characteristics of the surface. Specular reflections occur off smooth surfaces, and diffuse reflections occur off rough surfaces. When you say "specular is simply reflection from a light", that's just not necessarily true. Specular is a reflection of ANY light rays (whether from a light source or from a bounced reflection off something else) off a SMOOTH SURFACE. It's the surface characteristics that describe specular, not whether it's a reflection from a light or not.
EVERYTHING WE SEE has reflection, or we wouldn't see it because light wouldn't bounce off it and into our eyes. EVERYTHING. And at one end of the scale of smoothness is a mirror, with a fully reflective surface, and at the other end of the scale is a super rough surface that only reflects a very soft, dispersed light. But it's all just a matter of degree of reflection.
One might even imagine a single "Reflection" slider for a surface shader that combines all of the reflection-related channels into one. With the slider at one end the surface is a mirror, and at the other end it's a very rough, diffuse surface. That's a gross over simplification, but hopefully it makes the point.
Now 3D software has to come up with some ways to separate that reflection into workable components. That's why we have separate color (which is diffuse) and highlight and shininess (which are specular) and reflection and SSS and translucency controls. It's ALL about reflection.
Anyway, let the trashing begin....
No trashing or name calling, because I think we may be saying the same thing, just in a different way.
When light hits a surface, there are basically four things that can happen to it:
- it can get scattered. Yes this is still a type of reflection, but because it has no defined direction, it can be treated as a separate category and indeed this is done so by Carrara, as the "color" channel;
- it can get absorbed, so no further calculations needed (but this is what contributes to the perceived colour of a surface);
- it can get transmitted through the surface - this opens up a whole new range of options such as transparency, SSS and translucency, but let's park that for now;
- it can get reflected (in a directional sense), this reflection can be "true", ie the angle of the light hitting the surface equals the angle of the light leaving the surface, or it can be blurred, so there is a random offset applied to each ray of light, but there is still some directionality (otherwise it would be diffuse as above).
What I am saying is that in the real world, there is no distinction whether the reflected light comes from a light or from some other source, such as a nearby diffuse surface, or a glowing surface.- light is light! However in Carrara, there IS a difference. The specular light from what Carrara defines as "lights" is controlled by the highlight and shininess channels, while the reflected light from other objects is controlled by the reflection channel, and here you can define whether it is sharp or blurred, in the same way as a specular highlight can be sharp or blurred using the shininess channel.
In physically based renderers, these parameters are controlled by the same set of controls - light is light. What I am saying is that people need to be aware of the different ways these are handled in Carrara in order to set them accordingly.
I hope this removes any confusion.
Jon, you are quite correct that blurred reflections should ideally be used in many cases. For a long time I have avoided them due to the render time hit - but having tried it recently, it is not such as big hit as I remembered. I have attached a quick and simple test, rendered with Sky Light, Full Indirect Lighting and blurry reflections on the plane set to 20% reflection, 40% blur and Fast. I think the result is pretty acceptable, and on my recently purchased laptop, render time = 40 seconds. That's too much of a hit is it (for comparison, a version with non-blurred reflections took around 20 seconds). And this is for an image where a lot of area is taken up by the blurred reflection surface, often it will only be a relatively small part of a render.
So don't necessarily rule it out!
Whoa, that's an interesting result for sure, Philw. I haven't tried blurred reflections in a long time, maybe in the latest beta versions they've fixed it to make it a do-able function?
When I tried it I was rendering a V4 with it and the render time was off the chart - not that big of a render, and something like 12 hours of render time, which was why I concluded it was not a feasable solution.
Yeah, I hope we removed any confusion you may have had... :)
Y'know, there's no dishonor in admitting you learned something.... :)
Yeah, I hope we removed any confusion you may have had... :)
Y'know, there's no dishonor in admitting you learned something.... :)
I was not confused - but maybe I expressed it initially in a way that was not 100% clear to you.
I learn stuff every day, from reading, from trying stuff out. No-one knows it all.
PhilW said:
stick around and you'll find out that's not exactly right ;)
Oh, come on Phil...even your "clarification" was a confused jumble of stuff that reflects some basic misunderstandings and a lot of confusion on your part.
But I will never win this, so I won't try. And the vultures are starting to circle so I'll quietly move on.
Someday I'll listen to Rashad and learn to let things go.... :)
Oh, come on Phil...even your "clarification" was a confused jumble of stuff that reflects some basic misunderstandings and a lot of confusion on your part.
But I will never win this, so I won't try. And the vultures are starting to circle so I'll quietly move on.
Someday I'll listen to Rashad and learn to let things go.... :)
If you'd care to point out what I got wrong, or point me to an article somewhere, I'd gladly learn more. You can even PM me if you don't want to do this publicly, and perhaps we can have an informed, polite discussion about this. I don't think it is enough to say I got things wrong without saying what they are. Maybe I have over-simplified - I am not a physicist (are you?) but I do have a sound scientific training and decades of experience of 3D applications, and I think that for most practical purposes, what I said was accurate and helpful.
Just an update on blurred reflections and how long they take to render. I'm just trying it on V4 skin and it IS taking a long time to render. I think the issue is arising in areas such as under the chin, where you have two surfaces with blurred reflections able to "see" each other. A blurred reflection is having to sample many multiple rays for each pixel, and if each of these hits surfaces which also require multiple rays, well I think you can see how this can quickly escalate into requiring huge numbers of calculations.
That's not to say don't use them - but maybe use them with this in mind and use them carefully. It will still be done by the morning...
This discussion often pops up in the Bryce forums as well. Specular is not only a commentary on the roughness of the surface, it also tells you a lot about the light source and the way its illumination is concentrated. All lights in theory create specular, just it might be very soft due to the wide angle of the light emitter, like the sky for instance. I think Phil's description of the way these softwares handle specularity vs reflection when rendering is spot on. I feel absolutely certain that Phil knows well what the difference between reflection and specularity are in real life. But when it comes to the applications the rendering engines really do handle them separately. Specularity for my mind is an abbreviated version of reflection that only applies itself to point type lights. Like Ambience, Specularity is somewhat of a throwback to a time when a full reflection calculation would not have been worth waiting for. In many ways we are still in an epoch where true reflections are often too costly to calculate.
Thanks for that description, Phil, it will be helpful in the future when explaining specularity vs reflection to new users. Specular applies to lights (point lights in particular), reflection applies to surfaces. Makes good sense. Fun fun!
thanks for your work in this PhilW.
I think we should have a Carrara medal to give out to the likes of yourself ;)
Really? So, as usual, I go thru a whole lot of time and effort to post information, and you guys can't even squeeze out one drop of respect or appreciation for my efforts? Really? It's all about sticking up for your buddies and discrediting anyone who challenges them?
I will never ever understand you guys.
thankyou Joe, I really appreciate the kindness, good feeling, warmth and generosity that emanate from your posts.
Joe Joe Joe....
Edited:
Let's talk a bit in Private Messages.