Modeling Sunlight Inside - Daylighting In Chief Architect?


Pascalli
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Hello,

 

After searching the forums and help files, I can't seem to find any good information on this.  I am trying to figure out how to accurately render sunlight as it comes in through the windows into living spaces.  This is crucial to getting a feel for whether the windows and overhangs are effective enough.  Most references to sunlight settings I have found are in reference to full perspective overviews, rather than actual POV cameras inside the house. 

 

How can I remove all light sources (I believe I have figured this out by putting a fixture in each room and turning it off), and configure sunlight to accurately come in through the windows (at given times and dates) so that I can see realistically how daylight will interact with the room when all lights are turned off? 

 

Thanks!

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You have to move the sun on the side where you want the sunlight to go through the window. Easily done using the adjust lights, the sun is in there. I like to put the sun in the corners for good shading, like 225 , 315, etc. but you may need to use a straight on sun to get it to poke through a window.

You may also check the suns height and lower it for better results

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You can set your time zone, latitude, and longitude in Preferences > CAD > Sun Angle

 

There are CAD line tools for a North Pointer and Sun Angle. The dialog box for the Sun Angle Line lets you set a date and time to project the sun at any time of day.

 

I don't think you need to use the north pointer line of north is the top of your screen. If north is another direction, the sun angle line will be relative to the north pointer line.

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From Pascalli post it sound to me like he wants as true as possible representation to evaluate shading.

 

(For rendering purposes I edit the default sun angles to the same numbers as you 65, 155, 245, 335 for each of the 4 elevations)

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If all you want is a pretty picture, use the default sun and adjust as needed to get it to shine in your window.

 

If you want a realistic model of the sun light, you need to use a sun angle.  You need to set the correct lat and lon as well as the time and date.  You can use several of them if you want to show different times and dates.  Also, you will need to setup a north pointer if true north is not straight up in your plan.

 

As far as getting it to actually shine in the windows, the first thing is to make sure it really would shine in the windows.  If you turn on the shadow in your plan view, it's pretty easy to see where it is going to shine.  As far as the camera views, I don't think it matters what type of camera you are using so you should be able to use a full camera inside your building to see the sun shinning in the window.  You will probably want to use the raytrace view to get the best results.

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Additionally, you can adjust the intensity of the Sun per rendering on the "Light Data" tab of the "Edit Ray Tracing Dialog" as well as control its shine direction. All the above factors (North Pointer, Sun Angle, Lat-Long, Intensity, render area lighting) effect the outcome. You control them to get the end product you require.

 

DJP

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Thanks for all the responses, everyone!  Yeah - I have added the North pointer, and set the lat-long, date, etc in the cad preferences, added a light to the room I'm interested in, and set the light to off.  Then, I generated a camera view in the room to render what it looks like, and there is light, but modifying the windows doesn't seem to make much difference.  I unchecked the sun in the lighting options (at this point there are no light sources in the list with a check beside them), and everything looked exactly the same.  With no light sources, I would expect the room to be pitch-black, or at least obviously darkened to a night-time appearance.  The fact that toggling the sun makes absolutely no difference leads me to believe that it is not being accounted for.  If I generate a view with shadows, then shadows are added, but, of course, I can't move around in that view and I'm not sure if it actually models the sun properly or just adds shadows.  I will try a ray trace and see how that looks, but those take a long time to generate.  

 

This room has south facing windows, and I am modeling for summertime in the middle of the day, so I would expect to see some light variation.

 

I did note, though, that the default light source is not showing up as it does when no lights are defined.  

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Ok, I am attaching the plan I am working with.  It should be noted that I am not intending to use this plan to generate our actual drawings, and am more using it to model ideas - it is a work in progress, done by a non-professional.  I just can't seem to get it to render sunlight in camera view.  In the meantime I will start a ray trace to see how it looks.  Thanks for the offer to take a look.  I should also mention that I have tried it with a light (deleted in the version I uploaded) and without.

Plan.zip

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Thanks!

 

Ok - feels strange to see someone else working in my plan.  I'm using X5, but the same options seem to exist.  Sorry about the maddening structures - the whole thing is really just built up to help visualize and determine layouts.  

 

We get plenty of daylight up north, I swear!  I think you hit on the bigger problem with the overhang and the porch.  The the thing is, though, that I would expect the amount of light in the room to change as the sun moves across the sky, even when it isn't shining right into the window.  It seems as though the software is only modeling direct sunlight, and not taking into account the overall amount of light that would be making it through the windows.  

 

I am trying to accomplish two things: 1) determine if I have enough windows to prevent the house from feeling like a cave and 2) calculate the effectiveness of overhangs to prevent direct heat gain during the summer while allowing for solar gain during the winter.  

 

Using the outside view, like you demonstrated, I think I can achieve a pretty good idea of my second objective.  I'm thinking that without some sort of adjustment for indirect light, though, my first objective will be a bit more difficult.  

 

The video was great fun to watch, by the way.

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Chief OTB, without changing any settings, has ceilings that are way too dark ... so, if you already have a check mark in the lighter ceilings box, you may want to change your ceiling to be more emissive.  Another adjustment that I usually forget to adjust, but then quickly change, is the interior ambient setting for a room.  You can also tweak the appearance of a ray trace after it is completed (actually I think you can do this while one is generating as well) by adjusting brightness, contrast, etc.  There are other things you can play with that will change the appearance of your ray traces in a good way.  I suggest that you go to the old ChiefTalk forum and check out some of the threads where ray tracing and lighting are discussed.  Users such as Jintu ... and many others ... give some good advice on settings to use, etc.  If you haven't watched the 3-part Chief bathroom videos on ray tracing, you should check them out as well.

 

I think Scott thought you lived at the North Pole and therefore your igloo was constantly dark.  Obviously, if you have lots of windows in a home, and it is not in any of the darker months of the year, you should have decent natural lighting in a room, even with eave and porch overhangs providing shading.  With that in mind, the exercise then becomes one of doing whatever setting changes you need to have to get the look you want.  Unfortunately, that isn't very easy given that there are literally dozens of settings you can alter to affect your room's appearance with Chief's camera tools.  When you master it, let me know what you did, because I have really struggled with making good ray traces forever.  Good luck.  When you get some results you are reasonably happy with, post them here so we can enjoy them as well.

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If you want an easy way to put the sun anywhere you want,  without sun studies, just delete the sun angle and adjust it manually and put it anywhere you want, I never use the sun angle. You can place it anywhere around the building in 3 seconds, using degree's of a circle. I may not be actuate but its fast and easy. .

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Glenn:

 

last I looked (a few years ago) Sketchup was way easier to control

and way easier to make animations

 

perhaps that has changed

but I doubt it

 

also the OP is in the play around stage

and probably doesn't have a "complete" model yet

 

Lew

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If you want an easy way to put the sun anywhere you want,  without sun studies, just delete the sun angle and adjust it manually and put it anywhere you want, I never use the sun angle. You can place it anywhere around the building in 3 seconds, using degree's of a circle. I may not be actuate but its fast and easy. .

 

That works if you are just looking to get sunlight into a rendering so that you can make it look nice, but what I am trying to do is model lighting as close to real life as possible for any given date/time.  I don't want my room to look nice and sunny and then it turns out to be a cave when it's built.

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Ok, I am attaching the plan I am working with.  It should be noted that I am not intending to use this plan to generate our actual drawings, and am more using it to model ideas - it is a work in progress, done by a non-professional.  I just can't seem to get it to render sunlight in camera view.  In the meantime I will start a ray trace to see how it looks.  Thanks for the offer to take a look.  I should also mention that I have tried it with a light (deleted in the version I uploaded) and without.

I was just going by your statement earlier, sometimes the sun will never be the way you want it to be, so in those cases, fake it, just for the view. Who really knows if Chief's sun is totally accurate to begin with anyway. I wouldn't guarantee it.

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Chief's solar calculator should be very accurate. The calculations done were the same as those used by NOAA for their calculator and we did comparisons to it when testing. I think their calculator is still using the same equations. If you do find an accuracy issue let us know.

 

As I recall the calculations should be very accurate until the year 2100. After that the accuracy will drop off but should still be pretty good until the year 3000.

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Good to hear about the accuracy!  If I could just get it to properly render indirect sunlight...

 

I will take a gander at Sketchup, though I think I remember looking at it once and being a bit intimidated trying to figure out how to make it do things.  Hard to beat the ease of doing simple things in Chief Architect (though it can get complex, as well).

 

The only problem I am having now is that in order to see shadows, I have to select "final view with shadows", which works fine, but then when I change the date/time, it doesn't automatically adjust like it did in the video from earlier in this thread.  Rather, it clears shadows and doesn't show them again until I turn the mode on again.

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