Getting more "natural" light inside?

[dann_stubbs]

Hello all,
a while ago I made an interior, and lighted it with just one bright light (the sun). The rest was radiosity/GI, and it worked out pretty good:

http://www.designme.be/works/studio3.jpg

Now, I'm making my girlfriend's bedroom, and used the same method. But in this case, there's only one window, and not alot of reflective objects, so it's very very dark. I tried making the sun a little brighter, but it hardly affects the darkness inside. Also, I tried placing a very soft light inside the room, but it just doesn't seem natural.

http://users.telenet.be/joyraider/kameran2.jpg

What are my options? :)

try looking through MV's tutorials

http://www.mvpny.com/RadTutMV/RadiosityTut1MV.html

there are 4 pages so check them all and i'm sure you will get some good tips

dann

[joyraider]

try looking through MV's tutorials

http://www.mvpny.com/RadTutMV/RadiosityTut1MV.html

there are 4 pages so check them all and i'm sure you will get some good tips

dann

great info, thanks alot!

I've set the Diffuse depth to 5 now... The "dark" render took 11 hours, I don't wanna know what it'll be this time; I need a renderfarm :D

[dann_stubbs]

great info, thanks alot!

I've set the Diffuse depth to 5 now... The "dark" render took 11 hours, I don't wanna know what it'll be this time; I need a renderfarm :D


render your "tests" at 320x240 while you are experiementing. these should go much faster and let you see what is happening without waiting for a full res render.

then when you are happy with the small renders, go up in size maybe still not full size and let that render to make sure all is well before you commit to the full res render. you will be able to do so much more rather then waiting days in between "tests"

dann

[joyraider]

render your "tests" at 320x240 while you are experiementing. these should go much faster and let you see what is happening without waiting for a full res render.

then when you are happy with the small renders, go up in size maybe still not full size and let that render to make sure all is well before you commit to the full res render. you will be able to do so much more rather then waiting days in between "tests"

dann

I'm only rendering at 480*360 atm, and that took me 11 hours :) I guess it has alot to do with the small round carpets (made with hair department), I'll take a look without them. I'm using a centrino 1.86 with 512 ram btw, if you wonder why it takes so long ;)

[dann_stubbs]

I'm only rendering at 480*360 atm, and that took me 11 hours :) I guess it has alot to do with the small round carpets (made with hair department), I'll take a look without them. I'm using a centrino 1.86 with 512 ram btw, if you wonder why it takes so long ;)


set a compositing tag and exclude the carpets from GI - it is doubtful that those are contributing anything to the light calculation.

also set a composting tag on anything glass or clear since that will not contribute to the GI solutions either.

and again if there are small but highly detailed items that will not add anything to the light solution - exclude them. think like a set of keys on a nightstand... it could be a lot of detail that the render engine has to try to solve while they would not contribute anything noticible to the light calculations.

dann

[dann_stubbs]

I'm only rendering at 480*360 atm, and that took me 11 hours :) I guess it has alot to do with the small round carpets (made with hair department), I'll take a look without them. I'm using a centrino 1.86 with 512 ram btw, if you wonder why it takes so long ;)

forgot to say - i'd still cut that res in half while doing your tests - it will be enough for you to see the light distribution and will cut the "test" time in half at least -then you can do more tests to get the right distribution before committing to the longer render.

and still exclude all that stuff like i said in the other email - it won't make any difference in the render result but should shave off a lot of time in the calculations.

dann

[joyraider]

http://users.telenet.be/joyraider/kameran5.jpg

wow, that went fast ;) about fifteen minutes.. I'm not completely satisfied though, it's still a bit too dark. Gonna set the Diffuse depth to 6 now, curious what it will be like. I'll post it here, thanks alot for your help in the meantime! :)

[dann_stubbs]

http://users.telenet.be/joyraider/kameran5.jpg

wow, that went fast ;) about fifteen minutes.. I'm not completely satisfied though, it's still a bit too dark. Gonna set the Diffuse depth to 6 now, curious what it will be like. I'll post it here, thanks alot for your help in the meantime! :)

don't forget to put the rugs back in and just put a compositing tag and turn off the "seen by GI"

also i'd probably jump up a lot more in the diffuse - go right from 5 to 10, then you can always split the difference down to 7 etc. make broad strokes at first then small ones later - like painting...

dann

[joyraider]

http://users.telenet.be/joyraider/kameran6.jpg

A bit better again, but still not satisfied :) Diffuse depth = 6 in this one. Will it look unnatural when I set the Diffusion to 10 or higher values? Will try some other things in the meantime...

[dann_stubbs]

http://users.telenet.be/joyraider/kameran6.jpg

A bit better again, but still not satisfied :) Diffuse depth = 6 in this one. Will it look unnatural when I set the Diffusion to 10 or higher values? Will try some other things in the meantime...

what you'll notice is the color bleed in computer simulations can be a lot more saturated then real life - but that is why we want small quick tests to nail down the settings -rather then waiting days between renders.

under the illumination tab for the shader color - there is a saturation setting - if you find one color is bleeding too much from the GI then you can lower the saturation of it - this is much better then trying to adjust the light since once the light brightness is right you can go to adjust the different shaders to add more or less "color" to the GI

dann

[STRAT]

i'd turn the diffuse to 1 and play with local ambient and diffuse omnis. should cut a couple of hours off your render times :)

[dann_stubbs]

i'd turn the diffuse to 1 and play with local ambient and diffuse omnis. should cut a couple of hours off your render times :)

since i could tell the user was more interested in testing and using GI - i figured i'd keep in the line of optimizing the GI rather then offering work arounds - just FYI

otherwise, yeah there are a whole bunch of threads on fighing with, um i mean working with GI ; )

i myself would rather fake the lighting to look GI, but at times i too enjoy messing around on a still frame and learning more about how GI in C4D "works"

dann

[joyraider]

Well, I'm pretty new with 3D & Cinema 4D (6 months ago I didn't have a clue what a mesh was or how to create 3D text), and I'm still very unexperienced with lighting. I still don't know the real difference between an omni or an area light, although I try to read as much as possible about lighting, architecture, etc etc.

Someone here told me how to use GI (radiosity in my C4D version), and I've been using it since. I think it's pretty easy to create an almost-photorealistic scene with it, even if you know very little about it - like me :)

The progress:

http://users.telenet.be/joyraider/kameran8.jpg

Hence the ugly spots right under the ceiling and between the closet/bed and walls. I've read that tutorial you gave me dann, but I'm not sure which settings to adjust to get rid of those spots (and it's kinda annoying to adjust something, wait 20 minutes, adjust something else, wait 20 minutes, ... ;) ). Any idea what to do in this case? The overall lighting in the room is satisfying for me though :)

[STRAT]

since i could tell the user was more interested in testing and using GI - i figured i'd keep in the line of optimizing the GI rather then offering work arounds - just FYI


Sorry Dan, yup, i did spot that, i know you know your gi :)
just thought i'd chuck in another idea for him to play with.

[dann_stubbs]

Well, I'm pretty new with 3D & Cinema 4D (6 months ago I didn't have a clue what a mesh was or how to create 3D text), and I'm still very unexperienced with lighting. I still don't know the real difference between an omni or an area light, although I try to read as much as possible about lighting, architecture, etc etc.

Someone here told me how to use GI (radiosity in my C4D version), and I've been using it since. I think it's pretty easy to create an almost-photorealistic scene with it, even if you know very little about it - like me :)

The progress:

http://users.telenet.be/joyraider/kameran8.jpg

Hence the ugly spots right under the ceiling and between the closet/bed and walls. I've read that tutorial you gave me dann, but I'm not sure which settings to adjust to get rid of those spots (and it's kinda annoying to adjust something, wait 20 minutes, adjust something else, wait 20 minutes, ... ;) ). Any idea what to do in this case? The overall lighting in the room is satisfying for me though :)

now you can see the higher the diffuse the more the light bounces in the room which equals greater brightness.

now that you can see those areas you can see the splotches - this is from too low of samples. when you see the dots during the pre-pass stage, this is showing you where the GI samples are placed. so it needs more dots in these areas.

you probably need more samples overall, so depending on what you in the min and max settings - just double them. once the low geometry areas look good you can just adjust eh max. think of the samples like that - min for minimal geometry and max for maximum geometry - this tells the calculation to put more samples in those respective areas.

you're doing great - the one thing that is good is you are trying. and the best way to learn is through trial and error. the thing with GI is it is never the same for each scene - so you need to get a grasp of what the settings do and how they affect the render.

and yeah - it is frustrating after a while when each render is 20 minutes, but think of how it would be if it was 20 hours between : ) and you can reduce your render size even more if you want to just get a super quick look at how the lighthing is. then when you are happy with the lighting you can turn off GI to render normally to get your textures set right - then you can turn GI back on and make the last tweaks to get it all looking good together.

3d is definately a technical use of art, and with practice comes great results and efficient render times.

keep going with it! and if you aren't sure what a compositing tag is (since you said you are new) select the area rug in the object manager then under the FILE menu in the object manager choose the CINEMA 4D TAGS and add a COMPOSITING tag to the rug geometry

a little vase icon will appear next to the rug geometry - now click that and below the settings will appear for that tag. under the TAG PROPERTIES you can uncheck the SEEN BY GI which will mean the object will render but the light calculation of the GI will ignore that object. something that is polygon heavy will take a long time to calculate - so this ignores it. so it can show in the scene but not contribute any to the GI solution (which in most cases a small rug won't contribute any color to the GI to make it worth the time)

dann

[jackb602]

Adding sky light will make an enormous difference in your rendering. As it is, you are simulating a bedroom in outer space, where direct sunlight is the only light source. Add a rectangular area light just outside the window with a pale blue color. This will really help distribute light in the room.

Jack

[joyraider]

After 51 (!) hours of rendering, this is where I am:

http://users.telenet.be/joyraider/ankamer.jpg

I'm very satisfied with the result, I must say :) I still need to add alot of objects to the scene (like a TV, detailed door, mirror, ...), but now I know my lighting is right ;)

Thanks for the help dann, and jackb602: I did what you told (the blue area light), it was a very good tip, it definetely makes a difference :)

I'll keep this thread updated ;)

Thanks!

[scanmead]

Bless you for starting this thread! I've tried just about every sort of lighting Cinema has in search of "realistic" lighting, and I do like using Diffuse Depth more than tweaking multiple area lights, just to find the shadows make no sense.

That tip about using the Saturation under Illumination solves the problem of controlling Radiosity independent of GI.

Just when I was about to pitch it out the window, the right questions were asked. ;)

lee

[dann_stubbs]

After 51 (!) hours of rendering, this is where I am:

http://users.telenet.be/joyraider/ankamer.jpg

I'm very satisfied with the result, I must say :) I still need to add alot of objects to the scene (like a TV, detailed door, mirror, ...), but now I know my lighting is right ;)

Thanks for the help dann, and jackb602: I did what you told (the blue area light), it was a very good tip, it definetely makes a difference :)

I'll keep this thread updated ;)

Thanks!

did you put a compositing tag on those high polygon rugs? that should help bring that time down a bit

dann

[jackb602]

After 51 (!) hours of rendering, this is where I am:

Wow, I didn't catch that render time earlier. You definitely shouldn't need to wait that long for a good render. Just for comparison, you might want to try a rendering in stochastic mode. It can be slow, but not that slow, and it gives you a good reference for the best quality Cinema is capable of. In any case, I'm sure you can cut that time way down experimenting with your GI settings.

Jack

[opay]

51 hours??? wow, try to decrease DD to 1 or 2, and place area light on windows with fallof inverse.

[STRAT]

Bless you for starting this thread! I've tried just about every sort of lighting Cinema has in search of "realistic" lighting, and I do like using Diffuse Depth more than tweaking multiple area lights, just to find the shadows make no sense.

lee

who says you need multiple area lights? ;)

that room render, at that size, using lower gi settings, could be rendered much more realistically in less than 5 mins.

[leed]

I agree with Dann, it is always good to know what the limitations of Gi are, or find out more about it, it is always good to learn about the lighting within C4d. As it is texturing and Modeling.
But i feel that you need to balance all the aspects of c4d lighting to get good results, it is just no good using one light and upping all the settings. I have never used a DD depth greater than 3, normally 1,

If you have a render time of 51 hours now, I dread to think how long it will be after you get all the other stuff in. you need to try and get that down, try reducing the DD to 2 and get rid of everything in the room but the bed and chest of draws.
Make all the materials white.

start with low settings though
Acc 70
PP 1/1
DD1
Stocs 300
Min 50
Max 100

Just keep testing.

Lee

[scanmead]

strat,

You have no idea how many times I've wanted to send you a room and beg you to fix the lighting. ;)

51 hours has to be unbearable. I've had DD up around 13-15 with only moderate increases in render time, even with samples and Min/Max set fairly high. It's only when Accuracy is increased over 80% that things come to a standstill.

lee (too) ;)

[nycL45]

I have noticed increasing DD from 1 to 2 increased the render time 400% (ouch!) with better results for an interior scene test output of 800x600. Upping the DD from 2 to 4 for a small render region sample was so slow that after 3+hrs of prepass, I quit. Higher DD settings will have to wait until I get a render farm.

Render Settings (GI)
S 100%
A 70%
PS 1/1
DD 2
SS 600
Min 100
Max 500

[scanmead]

hmm.. I just finished a test render of a room (only partially furnished) at 640x480 in just under 40 minutes, and that was with shaders using AO, no lights, using a luminous sky object for illumination.

GI Strenght 100%
Accuracy 70%
PrePass 1/1
DD 20 (!)
Stochastic 300
Min 100
Max 500

So, as always, it's a combination of things that push render times through the roof. Reflective materials and shaders using alphas can be a big drain, along with Area Shadows.

[joyraider]

hmm.. I just finished a test render of a room (only partially furnished) at 640x480 in just under 40 minutes, and that was with shaders using AO, no lights, using a luminous sky object for illumination.

GI Strenght 100%
Accuracy 70%
PrePass 1/1
DD 20 (!)
Stochastic 300
Min 100
Max 500

So, as always, it's a combination of things that push render times through the roof. Reflective materials and shaders using alphas can be a big drain, along with Area Shadows.

What is AO, exactly? :)

that room render, at that size, using lower gi settings, could be rendered much more realistically in less than 5 mins.

Are you referring to my scene? if so, please, tell me how! ;) I'm trying to get as much a wow-effect as possible :)

did you put a compositing tag on those high polygon rugs? that should help bring that time down a bit

dann

Nope, doing that right now, same with the sheets (cloth), saves ALOT of rendertime indeed.

[scanmead]

AO is Ambient Occlusion. You can use it instead of or along with GI in your render settings, but it will sloooww things down, and it's tricky to control. You can also use it in a Shader, by putting it in the Diffuse Channel (under Effects/Ambient Occlusion), to heighten shadows for just the objects you apply the shader to.

I'm not seeing anything in your room that should cause such huge render times. To do test renders, you could drop the Stochastic to 150, Min to 20 and Max to 40. You'll get blotchy artifacts, but the lighting will stay the same.

When your ready for a final render, increase those 3 settings a little at a time, and do Render Region samples where the artifacts are to see when to stop increasing them.

[handige_harrie]

Maybe this can be useful as well when talking about gi settings:
http://www.shademaster.nl/peter/radiositytest.htm

Started with this thread:
http://forums.cgsociety.org/showthread.php?t=265726

:)

[nycL45]

hmm.. I just finished a test render of a room (only partially furnished) at 640x480 in just under 40 minutes, and that was with shaders using AO, no lights, using a luminous sky object for illumination.

GI Strenght 100%
Accuracy 70%
PrePass 1/1
DD 20 (!)
Stochastic 300
Min 100
Max 500

So, as always, it's a combination of things that push render times through the roof. Reflective materials and shaders using alphas can be a big drain, along with Area Shadows.

The difference between our two tests is due mostly to lighting. You used a luminous sky object for illumination and I used two omnis, one for ambient w/falloff "off" and the other for ambient w/falloff "on", plus ten spots for downlights with shadow and falloff "on".

[scanmead]

Lights will do it. ;)

[Martin Kay]

Hello all,
a while ago I made an interior, and lighted it with just one bright light (the sun). The rest was radiosity/GI, and it worked out pretty good:

http://www.designme.be/works/studio3.jpg

Now, I'm making my girlfriend's bedroom, and used the same method. But in this case, there's only one window, and not alot of reflective objects, so it's very very dark. I tried making the sun a little brighter, but it hardly affects the darkness inside. Also, I tried placing a very soft light inside the room, but it just doesn't seem natural.

http://users.telenet.be/joyraider/kameran2.jpg

What are my options? :)

Well, just using an infinite light only accounts for 'directional' only sunlight, (through the window). Try using an area light with area/soft shadows at the window position to simulate scattered multi directional light which the sky and landscape would bounce in. Also a plane outside the window to simulate the sky or landscape as a luminant shaderw would also help to fill the darkness.

Martin K

[nycL45]

Lights will do it. ;)

Yep. I'm going to run some tests using the unknown scanmead/nycL45 blend method next.

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