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HolyMonkey-
12-15-2011, 02:45 AM
Hey there, I noticed there's alot of really skilled archetectural renderer guys on this forum, and I notice most of them have the same techneque.

http://www.ryste3d.com/index.htm

These guys for example. Brilliant work.


Does anyone have a good guideline besides the material on the individual objects on how to get the crispy, realistic effects? For example the heavy sunlight effect, I guess correct lighting is key for good archetectural renders? Alot of work done in post?

The famouse eXept guy i think he's called also gets this effect.

I would guess using a white BG, with a sky HDRi, or a huge lamp acting like a sun, then some spotlights to create some bounce inside the building?

I often get light leaks, and over exposed areas when I do this. Basically just looking for general advice when it comes to architetural rendering. Here's a scene I did.

Some heavy light leaks and over exposed areas.

http://img811.imageshack.us/img811/9208/beautyshotetasje01.jpg (http://imageshack.us/photo/my-images/811/beautyshotetasje01.jpg/)

biliousfrog
12-15-2011, 05:14 AM
If you want to mimic realism then you need to study the real world and how photographers use light and shade. Once you understand that you can apply the techniques used in CG to mimic the way that a photographer might view the scene.

Raytracing doesn't work in the same way as real light. Renderers like Maxwell and Fryrender are very close to being 'photo-real' but they are also incredibly slow so most people have to learn to cheat to a certain extent.

In Lightwave we have access to various light types, light emitting environments and global illumination to fake the real world, they are all required to nail realism. Another key ingredient is working in linear colour space.

If we start with an outdoor scene, which is often the easiest to get right, there are some very basic things we need to do. We need a sun that will cast straight shadows because of the distance it is from us. We also need a sky which will 'fill-in' the shadow areas and add ambient lighting to the scene.

Depending on the time of day, time of year, location and weather the settings for the sun and the sky will need adjusting. The sun's colour temperature changes depending on its location in the sky due to the dispersion of its rays through the Earth's atmosphere. At mid-day it will be a very bright yellow, at sun-set it will turn to a deeper orange or red.

The sky colour ranges from a deep blue on cloudless days to a dull grey when filled with rain clouds and a deep red when reflecting the sun during a summer's evening. HDR images can be used alone or in conjunction with a sun light to produce a realistic ambient light, however, they offer very little flexibility. My preferred choice is to use DP's sunsky plugin and allow the sunlight's position to adjust the sky accordingly.

The light itself ranges from a crisp, harsh light during mid-day sun in the summer with sharp shadows to a soft, diffused light on a snowy winter's day. Depending on the sunlight required a distant light could suffice, a dome light with an angle of 3-5 degrees would add softer shadows or, I like to use DP's infinite light. If you needs a very soft, directionless light a dome light set to 90 degrees or even just a bright background and GI will work.

Global illumination acts as a bounce light and is essential in adding the final touch to a realistically lit scene. The 'final touch' part is important as it shouldn't be treated as a substitute to a well lit scene. For exterior scenes 3 bounces is often enough with extra ones adding little to the overall look. Light will bounce from the ground and from object to object to fill in shaded areas.

Finally, we need to look at working in linear colour space. Depending on the Lightwave version you're using it can be as simple as checking some boxes or it can mean manually adjusting the gamma of images and colours and adding gamma back via image processing.

Matt Gorner's video tutorials cover the basics of using Sunsky and working with linear colour space, I recommend watching them.

Once you've nailed the lighting, the next step is using realistic materials and creating realistic models but I believe that a grey box can look great if the lighting is good.

HolyMonkey-
12-15-2011, 05:21 AM
Awesome description!

Do you have a link to the DP plugin site? I think I have it on my other computer which isn't here right now but would be nice =)

Matt Gorner's video tutorials link? I tried youtube but couldn't find his specific account name.

and im using LW 9,5

biliousfrog
12-15-2011, 05:40 AM
http://www.pixsim.co.uk/lightwave_video_tutorials.html

woops...I had to run off quickly ;)

biliousfrog
12-15-2011, 05:41 AM
http://dpont.pagesperso-orange.fr/main_en.htm

prometheus
12-15-2011, 11:48 AM
That image looks like a gym facility, that is something we have planned to do out of our 2 floor plans of our gym machines.

That wonīt be up until nex year thou, not sure if I will have the time to do it myself either, we will contact a 3d team later on and check on their prices thou.

but that image is a more lighter realism version to describe the facility, not going for the more advanced realism.

I would suggest take a look at dome lights, they are almost like distant lights, but can be softer..if you set the dome light angle to 0 it will be same as distant and itīs shadows..set it to 10 or 20 it will be softer in shadows but quite sharp.
If you simply clone that light, and set the angle to 90..you will have sort of ambient occlusion look too...to light up exterior parts a little softer.


Michael

HolyMonkey-
12-16-2011, 01:53 AM
That image looks like a gym facility, that is something we have planned to do out of our 2 floor plans of our gym machines.

That wonīt be up until nex year thou, not sure if I will have the time to do it myself either, we will contact a 3d team later on and check on their prices thou.

but that image is a more lighter realism version to describe the facility, not going for the more advanced realism.

I would suggest take a look at dome lights, they are almost like distant lights, but can be softer..if you set the dome light angle to 0 it will be same as distant and itīs shadows..set it to 10 or 20 it will be softer in shadows but quite sharp.
If you simply clone that light, and set the angle to 90..you will have sort of ambient occlusion look too...to light up exterior parts a little softer.


Michael

Thank you for your help, both of you. Keep the tips coming =)

Here's a problem I encounter quite alot, if I have an enclosed space such as the inside of a building I and I put the sunlight from the outside, and I have a roof. The room inside often gets very dark and dont have the overall light as shown in the link above.

Know how to solve this? Place a bunch of physical lights inside to act as a lamps?

and some spotlight facing inside the windows?

I have viewed some of the tutorials by that guy before he's brilliant. I need to refresh quite alot. I think he solved this problem by rendering out frames seperately and adjusting layers in Photoshop, however if you're going to have an animation hehe, that wont work

Danner
12-16-2011, 02:49 AM
To light an interior I use many shadowmapped spotlights with high rez cached shadows. After the first frame, (where the cache is written) they render very fast and give you soft shadows. For the windows I often use area lights but If the place has lots of windows and are big enough, a high intensity backdrop might work just fine and render way quicker.
Radiosity for indoor shots usually needs to be higher. Turn it up by adding more indirect bounces (but not more than 4, since it's hardly noticeable after that) more rays per evaluation. (between 400 and 2000) and a lower minimum pixel spacing. (between 1 and 15) The higher you go with rays per evaluation, the lower you can go with min pixel spacing and vice versa. It's a balance, quality with speed can be attained at 300 RPE and 1 MinPE or at 2000 RPE and 15 MinPE, the look is different so experiment. If you do go with a high MinPE ambient oclussion is your friend.

HolyMonkey-
12-16-2011, 04:01 AM
To light an interior I use many shadowmapped spotlights with high rez cached shadows. After the first frame, (where the cache is written) they render very fast and give you soft shadows. For the windows I often use area lights but If the place has lots of windows and are big enough, a high intensity backdrop might work just fine and render way quicker.
Radiosity for indoor shots usually needs to be higher. Turn it up by adding more indirect bounces (but not more than 4, since it's hardly noticeable after that) more rays per evaluation. (between 400 and 2000) and a lower minimum pixel spacing. (between 1 and 15) The higher you go with rays per evaluation, the lower you can go with min pixel spacing and vice versa. It's a balance, quality with speed can be attained at 300 RPE and 1 MinPE or at 2000 RPE and 15 MinPE, the look is different so experiment. If you do go with a high MinPE ambient oclussion is your friend.

When you use spotlights, dont you get alot of light areas? In reeal world light often blends alot and you dont have hard light.

I dont have time to experiment right now but I guess you set up the cone angle pretty far? Perhaps you have a quick screenshot example of a spot and some settings that would be used for an enclosed interior? hehe, thanks though alot of good info going on here =)

biliousfrog
12-16-2011, 06:49 AM
The only reason that interiors appear bright during the day without any interior lights is because our eyes adjust to the apparent lack of light. In photography the aperture can be opened up to allow more light in (just like an eye's iris) or a longer exposure can be taken to allow more light to enter the camera.

The reason that the room doesn't appear totally dark is because the light entering the room is reflected from the surfaces inside the room and bounced around. To simulate this in Lightwave (and other raytrace renderers) you would need to use bounce lights or radiosity (global illumination). Unlike exterior renders, it is often necessary to use more 'bounces' on interiors as the light gets trapped inside the enclosed space.

Again, using linear colour space will help a lot with the realism as you might need to increase the exterior light sources to get enough light into the room. Remember that lights go past 100%.

You will need to make sure that raytraced transparency is used on any windows.

With regard to your previous post, why are you using 9.5? Upgrade to 9.6, it is much more stable and has some much improved tools...it is free after all.

HolyMonkey-
12-16-2011, 07:10 AM
The only reason that interiors appear bright during the day without any interior lights is because our eyes adjust to the apparent lack of light. In photography the aperture can be opened up to allow more light in (just like an eye's iris) or a longer exposure can be taken to allow more light to enter the camera.

The reason that the room doesn't appear totally dark is because the light entering the room is reflected from the surfaces inside the room and bounced around. To simulate this in Lightwave (and other raytrace renderers) you would need to use bounce lights or radiosity (global illumination). Unlike exterior renders, it is often necessary to use more 'bounces' on interiors as the light gets trapped inside the enclosed space.

Again, using linear colour space will help a lot with the realism as you might need to increase the exterior light sources to get enough light into the room. Remember that lights go past 100%.

You will need to make sure that raytraced transparency is used on any windows.

With regard to your previous post, why are you using 9.5? Upgrade to 9.6, it is much more stable and has some much improved tools...it is free after all.

Thanks! I usually never go over 4 indirect and 16, and I always use 250-300 rays. Max min 1 - 100.

Im currently watching the tutorials you sent me , nice stuff!! and in regards to 9,6 have alot of animations made, back in school we had to use maya, and when you upgraded your older version scenes became broken, or couldn't be traced back to previouse version. Does LW have this problem?

prometheus
12-16-2011, 09:08 AM
I still have a buckload to learn when it comes to interior rendering, hereīs my first test samples, I had to abandon it for a while since I got full up with our product catalog and the machine rendering alone, maybe I get the time to finish a full environment with most of the machines together.

some samples of difference between linear and srgb output.
the srgb output can be to washed out thou, I need t learn how to avoid that, but other than that..it brightens up all dark areas.

Michael

HolyMonkey-
12-16-2011, 11:21 PM
I still have a buckload to learn when it comes to interior rendering, hereīs my first test samples, I had to abandon it for a while since I got full up with our product catalog and the machine rendering alone, maybe I get the time to finish a full environment with most of the machines together.

some samples of difference between linear and srgb output.
the srgb output can be to washed out thou, I need t learn how to avoid that, but other than that..it brightens up all dark areas.

Michael

srgb output? Taken into photoshop and raise the levels?

If its compatible, any chance I could get to take a look at your scene setup? I dont need your training equpitment models just curiouse to see how you setup your scene,

looks great dude!

biliousfrog
12-17-2011, 02:14 AM
... when you upgraded your older version scenes became broken, or couldn't be traced back to previouse version. Does LW have this problem?

The only problems I know of are opening LW10.1 scenes in to LW10, I haven't had any problems with previous versions (I'm still using 9.6). I've got files dating back to LW5.6 and they all open fine. The only issue's you might find are missing plugins but I've only experienced that because my older files were created in the 32bit application and I've been using 64bit for the past 5 years or so, so some plugins are no longer included.

One of the reasons for getting light leaks is probably because you aren't using enough rays and/or because the max. spacing is too high. Interiors with lots of furniture will eat up rays so you might have to increase the samples. My min-max settings are usually around 2 and 10. Except's radiosity guide explains the settings in great detail.

...another quick set of tips....

If you need to 'fill' a scene with bounce lights try using distance lights, which will not cast bright spots, or use single-sided area lights with fall-off.

Place single-sided area lights just inside windows with a short fall-off to cast light bleed around the openings and to scatter the light entering the windows.

For bright lights be sure to use luminous objects (hidden from camera if necessary) as they will show in reflections, lights won't.

HolyMonkey-
12-17-2011, 04:57 AM
The only problems I know of are opening LW10.1 scenes in to LW10, I haven't had any problems with previous versions (I'm still using 9.6). I've got files dating back to LW5.6 and they all open fine. The only issue's you might find are missing plugins but I've only experienced that because my older files were created in the 32bit application and I've been using 64bit for the past 5 years or so, so some plugins are no longer included.

One of the reasons for getting light leaks is probably because you aren't using enough rays and/or because the max. spacing is too high. Interiors with lots of furniture will eat up rays so you might have to increase the samples. My min-max settings are usually around 2 and 10. Except's radiosity guide explains the settings in great detail.

...another quick set of tips....

If you need to 'fill' a scene with bounce lights try using distance lights, which will not cast bright spots, or use single-sided area lights with fall-off.

Place single-sided area lights just inside windows with a short fall-off to cast light bleed around the openings and to scatter the light entering the windows.

For bright lights be sure to use luminous objects (hidden from camera if necessary) as they will show in reflections, lights won't.

Quick question, you set min to 2 and max to 8 ? I read his guide but dont quite grasp it. Wouldnt it be better to leave it at 1-100 to give a more accurate solution?