setting good light levels for lights vs. sunlight

[Ernest Burden III]

On to my next C4D issue--setting lights. The whole lighting situation in C4D strikes me as rather over-simplified. Everything is on the same 0 - 100 scale. If I set an indoor light to 100 will it really be as bright as the sun, if my distant light is also set at 100? As we have learned from physically accurate renderers, the sun is orders of magnitude more bright than indoor lamps. OK, no biggie. Is the solution then, to make all indoor lamps at brightness levels of, say 35, while sunlight is 100?

 

I set up an interior in Lightscape, sent it into FormZ and off to Cinema via VRML. All my lights come through, material base colors too, one view, very nice. But all the 'lightbulbs' are set at a brightness of 100, and the display and raytracings are whiteouts. OK, time to lower all 65 indoor lamps.

 

But is there a way to lower the overall brightness of the scene? I haven't found one.

 

Before sending my file to C4D, I ran the lights in Lightscape. I ran the radiosity with high settings in about ten mins., and then could raytrace a full-screen image in a few seconds. In Cinema, even without radiosity, a lowres raytrace is taking a very long time. I hope to get better with this program, because so far it isn't living up to what I'm used to, and cost a LOT more.

 

Back to work, learn the program...

[jackb602]

Ernest,

 

Unfortunately Cinema does not use physically accurate light intensities, so you'll need to fake it. The sun (or any light) can be brighter than 100; I often use 125-150. The real world has an enormous range of light intensities, but our monitors and printers are much more limited as you know. I do wish C4D allowed for accurate light intensities, as well as an exposure control for scenes lit by natural and artificial light. In fact these would be two of my biggest feature requests.

 

As for your interior with 65 lamps, if they are identical you can create one original light and make the rest instances. This way you only have to change the settings once.

 

Do your 65 lamps use soft shadows? This could be the reason for the slow render times. Either reduce the shadow map size, or turn off shadows where they aren't needed. Hope this helps.

 

Jack

[STRAT]

as you know, lighting is difficult to master.

 

and comming from a LS environment where you have accurate light intensities to something like c4d lights where it's a range between 1-100 (even tho you can go lower than 0 and higher than 100) it must be frustrating, but this is how it is in most other 3d apps too m8, so c4d is not allone. LS is

 

interior lighting is an art. i find c4d is much easier to get right than max/viz tho.

 

i'll typically put the main sun light, typically a distant light, set anywhere between 75-100% with ray traced shads, then i'll use instanted attenuated (most important, must be attenuated) omnis for all my interior lamps, and i wont determin the strength of these until i know how many i'll be using and what brightness i want the image.

 

and to get a general lightness i'll throw in a couple (literally 2 or 3) low light emitting omni fill lights.

 

but again, it's all difficult. each and every scene is unique, and sometimes even simple scenes completely varey in their lighting rigs.

 

as i say, to control the overall lighting intensity of the scene dont use ambiant (this should be off) and dont gamma control it, this is a poor fix. use your internal omni's.

 

i find it like this - treat it like real life -

 

make the internal room with no internal lights or ambiant turned on. everything should be very dark or black.

 

Externally, put in the sun light and your GI light dome and tweek until the outside lighting is nice. internal should still be darkish, as it would in real life.

 

Add an extra light bounce or a couple of low light emmiting omnis until you have the correct atmos ur after, ie, how the room should realistically look with just external sunlight comming in and no internal lights added yet.

 

Then just add all your internal attenuated lamps and adjust brightness/shadow intensity to suit.

 

this is obviously a rought guide, how i go about it. but there are other ways too. eg, further use of IBL, manipulation of FLOOR objects, material saturation levels, render tags, invisible GI casting objects etc etc etc. a whole host of things to play with.

 

In all honesty Ernest you're obviously a LS guru, why not stick with that? does it do all you want these days? because it certainly produces the best imagery i've ever seen.

i just hope you dont think C4D is a pain in the ass compaired to LS, because C4D, max, viz, LW, maya etc etc all act in much the same way.

[Gerri4D]

Ernest,

 

Lightscape is the much fastest one, why its materials are simpler (no bumps, no diffusion maps, no falloff no blurry......)

 

I have Lightscape from the version 3, and for the interior scene is the best, but you cannot manage scenes of huge dimensions.

 

So I have bought Cinema, than in the way to operate it is completely different from Lightscape, in radiosity is slow slow, in raytrace is enough good.

 

in order to obtain optimal renders, you must completely forgotten about the lights of lightscape.

 

Gerri

[Ernest Burden III]

Thank you, all, for the kind help. I do not mean to keep talking about Lightscape, but that is what I am used to. I still use it for all my work, but as we know it is a rotting carcass. It cannot animate objects. It does not have bump or diffusion maps, true, but it has procedural versions of both which do 85% of what you want those things for in architectural rendering (non-tiling surface variation) just like the nice 'noise' choice in C4D materials.

 

I can adjust to a 0 - 100 world (I knew there were 'negative' lights but when I put in a -50% it jumps back to 0--RTFM), the problem is that the trial and error method is so slow. Time is money, and waiting several minutes to render a test of one light group at thumbnail res is too much. I could buy a faster computer--mine is 1 year old.

 

I have 64 lights because that is the number of lamps in my interior space. I know about instancing them, I would have done that but am still learning controls, so I set 'em up in LS and just grouped them under nulls (fixtureA, fixtureB...) so I can quickly select all of one type and therefore adjust together.

 

I think when you have a program that can do nice, soft, or better yet area, shadows it is a shame to have to turn off these features to be able to get your work done. I tried setting my lights to better settings and let it work overnight just to see what was possible (with lots of STRAT tags to turn off GI for furn.). I got up to 7 hours of rendering and it's 1/5 through a PAL res image. Unworkable.

 

I am sorry to be negative, I don't like whiners and I'm sounding like one.

 

I never thought lighting was hard to master. Strat--by 'attenuated' do you mean falloff? If so, do you use linear? And I notice the default distance is 500 whatevers. That seems like a lot of range for a light in either meters or feet. I set them to 50 feet, but even that is arbitrary.

 

C4D is a much more capable program than LS in MANY ways, and I haven't even tried modeling in it yet. The stochastic rendering with low samples produces a beautiful result (my version of beautiful). I'm just having trouble adjusting to all the compromises and workarounds. It's true, every other rendering program is basically like this. They shouldn't be.

[STRAT]

Forgive me if i'm going over something ur familier with here, but.....

 

if you just put in an omni into ur scene it will cast light over an infinate radius.

using falloff limits this. attenuation is falloff, but by using the near/far clipping values you get a far easier control of things.

 

look at this image of a simple omni i've placed in the scene -

 

 

 

under the light's details tab there is a near/far clipping option at the bottom.

 

i use the far clip option. i always set the "from" to 0 and the "to" is the distance you want the light to eminate (see the green circles in the scene) and because they have grip nodes you can actively pull these out to a live size on-screen instead of spinning a value in the box.

 

all your interior lights can be instanced back to this 1 light too so make changes to this and they all change.

 

this is how i control my scene's lighting. i generally keep all other falloff options as they are and use the far clipping option exclusively.

 

as i say, attenuation is an essential. really makes lighting the scene so easy and controlable.

 

(i pressume you've switched off the Autolight option in the render settings options too?)

[Ernest Burden III]

attenuation is falloff, but by using the near/far clipping values you get a far easier control of things

 

OK, easier is better. I'll try switching from a falloff amount to that one. They did seem redundant.

 

 

i pressume you've switched off the Autolight option in the render settings options too?

 

Presume nothing where new-to-app persons are concerned, idiocy may still be in play! I read that 'autolight' only was used when no other light was present, so I thought that it would not be a factor once any lights were on. I will happily turn the little bastard off.

[STRAT]

Presume nothing where new-to-app persons are concerned, idiocy may still be in play! I read that 'autolight' only was used when no other light was present, so I thought that it would not be a factor once any lights were on. I will happily turn the little bastard off.

sorry, you are correct

[brehaut]

I have been sitting in the backgroud reading this post and will give the far clip a try as i have been having a lot of trouble lighting scenes as well ,to the point where it it is frustrating i cant help but think that cinema is extremely capable but with my lack of lighting experience i havent been able to good resault. so i am hoping far clip will help

[Wokka]

G'day,

I must say I totally agree with Mark. I bought C4D based mostly on it's radiosity ability for architectural images. I been constantly dissapointed with it's ability (maybe mine too) and primarily it's render time. Rendering internals takes forever at any decent size for print (ie 3000 pixels) and has quickly become impractical. Using lots of fill lights etc is the only practical method of achieving reasonable results in resonable time and ignore radiosity altogether. I sometimes run a tiny (300*200) image to check how my fake should look, but even that becomes prohibitive. Maxon really should look at this speed issue as it claims to be great software for architectural presentation, but I see very few renderings that use radiosity in the galleries except if they are of empty halls or rely on renderfarms etc.

[Wokka]

BTW, thanks Strat for the quick tutorial and tip on far clipping. We aussies are now a good 12 hours ahead of the rest of the world!

Cheers

[Ernest Burden III]

We aussies are now a good 12 hours ahead of the rest of the world!Cheers

 

Not so fast! We Americans work late.

 

The interior I am writing about is the same one I've been working with (and posting), so here is an update. The scene in C4D is settling down, but I still have light levels that are not right. Adjusting setting and re-rendering to see what I get is taking too long. It's fine for a learning excercise, but unworkable for production. So here is a C4D image, and the same file, same lights, in Lightscape. The Cinema one took 1 hour 5 mins. to render at this resolution, while the LS was lit, tested re-lit, tweeked, etc, and then raytraced (took about 12 seconds) to twice that res. in the same time.

 

Yes, I do have the lights set to 'soft' shadows. But that's the way lights behave indoors, I should be able to use it.

 

So onward with my Cinema education...

[Ernest Burden III]

While I have abandoned the plan to use C4D for the interior rendering (I actually have to get this project handed in one of these days) I am still using Cinema for the exteriors, one aerial view and one ground view (that one is an awful viewpoint, at client's request).

 

You cannot really see the brick textures from this scale, but I managed to map them. I'm having great fun using noise in the diffuse channels, scaled up. It makes great roof tiles (slate-like) with the 'mod noise'. It's annoying to have to map coords for everything instead of having them default to the mapped polygon's extents when you drop a material on a poly. The default projection seems to be spherical, not flat.

 

Trees will be put in to cast shadows but not be seen, then matted in Photoshop, post.

[leed]

Ernest

With relation to the problem about switching un-selected objects off (different thread) to consentrate just on the object you are working on.

http://www.tools4d.com/

Have a look at the 10 com tools plugins for sale, there is a plug in that does just what you want and it costs 79Euro's

Lee

[Ernest Burden III]

Trees will be put in to cast shadows but not be seen, then matted in Photoshop, post.

 

I was liking the way the trees looked, so I figured I would have them render.

 

Bringing them in from Lightscape was a nightmare. I got the file to transfer via 3ds, untriangulated it. But the maps, which were just .tga files with an alpha channel in LS, had to have the alphas manually assigned in FormZ. Why? Do we not know that tga files can have alphas, and maybe we would just want a damned button for 'use alpha'? Too easy I guess, you don't think you are using expensive software if it's easy. Sent the file into Cinema, and found I had to go back and manually assign the tga's for the alpha material channel AGAIN, since the 3ds transfer put them all in under the transparency channel, ehich does not work as well as a true alpha.

 

So that was a lot of frustrating work. Now, to have the things render...

 

I want the image maps to be self-illuminated--no shadows or specular effects, or variation by angle to camera. The luminance channel? Yes, but strong values burn the textures, and I still get shading on them which I do not want. How else to do this?

 

I set a light to 'ambient' and using it, no shadows, gets the result I want, but now to have the trees cast shadows they must be seen by the sunlight, and then they pick up shading effects.

 

So how to have maps visible to camera and rays and cast shadows but render 100% flat?

 

Oh, and the trees do not want to display in the regular shaded view, only in wireframe. I'll puzzle over that one, tonight, as well.

 

I'd post an image if I could get one to render the trees...

[Ernest Burden III]

I'd post an image if I could get one to render the trees...

 

This is neither a good 'flat render' nor a regular one for these tree maps, but it shows what I'm trying to do.

 

The second image is what I want to do--which works in one file but not my main one...

[STRAT]

Sent the file into Cinema, and found I had to go back and manually assign the tga's for the alpha material channel AGAIN, since the 3ds transfer put them all in under the transparency channel, ehich does not work as well as a true alpha.

 

yes, this is frustrating for imports via 3DS format. if i import like a crowd of 40 or 50 opacity mapped people from another app into c4d, i have to spend an age re-assigning the alpha map into the correct channel.

 

 

I want the image maps to be self-illuminated--no shadows or specular effects, or variation by angle to camera. The luminance channel? Yes, but strong values burn the textures, and I still get shading on them which I do not want. How else to do this?

 

hmm, i usually just use the illuminance channel with no problem. look here -

 

 

 

this render had just the illum channel set to 100% (with img map in channel). no gi, no other lights in the scene atall. turn autolight off too. i used a plain backround object too with a white material.

 

 

I set a light to 'ambient' and using it, no shadows, gets the result I want, but now to have the trees cast shadows they must be seen by the sunlight, and then they pick up shading effects

 

so you want to render an object which recieves no light from the lights, but still casts a shadow? you may have to mess with exclusions and setting up a couple of extra individual lights, but this is the concept, and it works a dream -

 

make 1 omni light casting a shadow, set to a brightness of 100%, copy it, turn off the copyied light's shadow, and set it's brightness to -100%. bingo.

 

look into layered psd rendering too.

[leed]

"I want the image maps to be self-illuminated--no shadows or specular effects, or variation by angle to camera. The luminance channel? Yes, but strong values burn the textures, and I still get shading on them which I do not want. How else to do this?'

Ernest

Have you tried using the image map in the luminance channel?

you can adjust the intensity by having a mid to dark grey in the colour picker and adjust the mix sliderto get the level you want.

lee

[Ernest Burden III]

so you want to render an object which recieves no light from the lights, but still casts a shadow? you may have to mess with exclusions and setting up a couple of extra individual lights, but this is the concept, and it works a dream -

 

make 1 omni light casting a shadow, set to a brightness of 100%, copy it, turn off the copyied light's shadow, and set it's brightness to -100%. bingo.

 

look into layered psd rendering too.

 

I have one light that only hits the trees, and then the sun would have to see them to shadow...that has been the problem.

 

I was going to render two times, one to get the trees right and one to get the shadows right, using the layered PSD file so I can drop one into the other.

 

Still, I would rather not render twice since C4D is not a very fast renderer. (Maybe it is, compared to other programs).

 

Have you tried using the image map in the luminance channel?

 

That is the one thing I have NOT tried, I thought that using the map there would cause an overly contrasted image--obviously I'm wrong. In this case, the pain of manually putting the maps into all the tree materials is too much to bear.

 

In C4D there does not seem to be a way to have a texture simply 'fit' polygons. I'm used to simply dropping a texture onto a polygon and having a map auto-size and auto-orient to it. So since each polygon of the trees came into C4D sized via the 3ds file, I think I'm forced to keep the materials as created, even though they are redundant (the 3ds export made a seperate file for each layer no matter if I had 'single file' checked in FormZ).

 

Again, this stuff is so easy and quick in Lightscape, the alpha is one click, so is 'self-illuminated' WITH shadows, it takes seconds. I don't want to spend days making C4D do the same the hard way.

 

While you guys are nice enough to be helping me with these beginner issues, any comments on the WIP?

 

I would like to make the glass on the L shaped taller building more reflective, but am using STRATglass and it is great, just not reflecting as much as I would think it ought to.

[leed]

Ernest

The image is looking nice, Is this a frame from an animation or just a series of stills?

I am not sure about the sun position for this view I always try and avoid the shadow casting light being directly behind the camera.

Some times I apply a very subtle bump to the glass just to give a bit of 'wave' to the reflection, be careful not to make it to strong.

I like the slate roof texture never thought of that.

If you want the trees to render shadows but not object then apply a compositing tag to all the trees and switch seen by camera off.

Also you can fit a tex to object, but when you import from Z all the object orientation is alined to the world co-ordinates, and the Fit textures, alines to the object orientation, this is a bit of a head ache. and I have spent hours correcting the object orientation on models.

 

Lee

[Ernest Burden III]

Ernest

The image is looking nice, Is this a frame from an animation or just a series of stills?

I am not sure about the sun position for this view I always try and avoid the shadow casting light being directly behind the camera.

 

I am doing this aerial, a ground-level and an interior. The sun angle originally was to the right, which is what I would prefer, also. But the 'new' part of this addition to an existing hospital is both the little pavilion with the tiled roof, but also the ambulance entry at the left. The client wants to be sure it all is in light. Also, this angle is better for the entry view (I'll post the WIP of that soon).

 

As usual for me, the digital render will be heavily worked in Photoshop for the final.

 

Lee--how old is your kid? Actually, I see that 'wokka' also has his kids for an avatar.

[STRAT]

it's a shame ur having all these teething problems switching over from LS. perhaps you got set in ur ways too much in LS. i didnt have half the problems u seem to be suffering with.

 

it's strange you find the AR slow too. internal renders can take some time if you want high settings, but externals? it'll shoot through those like they're not even there usually.

 

can you explain what exactly you want with the trees? i pressume you want the main sunlight to shine on them and project shadows from them, but not actually illuminate them?

[Ernest Burden III]

it's a shame ur having all these teething problems switching over from LS. perhaps you got set in ur ways too much in LS. i didnt have half the problems u seem to be suffering with.

 

Set in my ways, that's me all right. But I'm just trying to do what I do now in LS because that is how to get the result I expect. There are probably easier ways to do stuff in Cinema than how I'm doing them, comes with usage, but I've used enough rendering software for enough years to have certain expectations of any of them.

 

Lightscape renders MUCH faster than Cinema. It's not even close. I will get faster images out of C with experience, obviously.

 

can you explain what exactly you want with the trees? i pressume you want the main sunlight to shine on them and project shadows from them, but not actually illuminate them?

 

Right! Because then I can have a seperate light illuminate ONLY them flat. Alternatively, a simple way to make the trees display their maps flat, self-illuminated. As I learned a few posts ago, the answer seems to be the map in the lum. channel then play with settings. But there's too many of the little bastards. Next time. Matter-of-fact, if I save out the trees set up the way I like 'em in C, I will not have to ever do this again.

[leed]

Ernest

How many tree types do you have in the image?

I had a bit of trouble when I first switched over from Z to C4d but is is worth the head ache C4d is a great app.

and as you said once you have done it once.........

 

my boy, he is 2 and 4 months the picture was taken around 8 months ago.

lee

[Wokka]

Ernest,

The boys!

They are 4 and 1 and they are our life.