[brodie_geers]

Did a test to see how shadows are working with HDRI lighting now for exterior scenes. The results I got are pretty much identical except for a slight change in color. Do noticeable shadow change. Am I doing something incorrectly? It seems like, realistically, there should be some fairly sharp shadows being cast from such a bright sun.

Maxwell 1.7


Maxwell 2.0


HDRI file used (reduced image size to post here and saved as jpg)



-Brodie

[3dtrialpractice]

is this an acctual .hdr file that u used to do lighting with?
becasue v2 is AMAZING in doing sharp shadows from hdr.. i was totally blown away..

Also if it is a .hdr it could be that it just dont have much dynamic range.. you can check this in photoshop cs2+ and see values as you lower exposure..

Go to the http://resources.maxwellrender.com/ site adn click the HDRI link.. there you will find a AMZING hdri for test: "street at dawn.hdr" i see it as the second hdri in the thumbnails.. or use one from the HDR folder installed w V2..

set it in your illum/reflection/background channel..
Here is render I did withthe street at dawn yesturday.. it was AWSOME.. totally clean and sharp shadows after 10mins on my computer!!!

notice it has a reflection of the sun on the window.. so in thise scen the sun is facing the camera.. the main shadow is towards the camera.. AND there are SHARP shadows coming from the suns reflecton (in the building inthe hdri image)
i was WOWED by this V2 power!

[Maximus3D]

How can you get shadows pointing in two completly different directions if the sun is the only source of light in the hdr.. i don't get that.
But it still looks great!

/ Max

[3dtrialpractice]

there is a SWEET FREE ap to let you preview and look at radiance values.. called HDRview
http://www.debevec.org/FiatLux/hdrview/

the download is a zip 3rd 4th paragraph down on this linked page..
Its just the HDRview.exe zipped.. at least thats hows ive had it for years.. and I but that in my c:progrmafiles directory..
I right click on a .hdr image and say open with>choose program... and the BROWSE to the programfiles directory selecthe the hdrview.exe AND MAKE SURE TO CHECK: always USE the selected program to open this kind of file (in the open with window)

now everytime i double ckil an .hdr it opens it quick with hdrview.exe...
AND you can mouse over parts of your .hdr image and On the TOP left of the WINDow will give you readouts.. of your pixwel location.. and MOST important your color info for that pixel.. inthe streetatdawn.hdr the sun is a value of 21,000.00 15,000.00 11,000.00 !!! wow thats intense.. basically you WANT the sun to be as much over the value of 1.00 as possible the brighter the better for sharp shadows..

the hdr you posted looked like the sun was only in the 1.0 range.. the image looks super flat. and maybe that why your not getting sharp shadows..


also with HDRview.. you can use the "+" and "-" keys on your keyboard to go up/down in expoure as weel as other shortcuts explaing inthe html abover.. (or right click on .hdr image and it will give you options.. like zoom in out) you pan your image by ckicking and draging it..

-hope this helps

[brodie_geers]

That isn't the actual file. I converted it to .jpg from .hdr in photoshop to post it here. It's from a package I bought from Dosch.

-Brodie

[3dtrialpractice]

How can you get shadows pointing in two completly different directions if the sun is the only source of light in the hdr.. i don't get that.
But it still looks great!

/ Max

MAX.. the reason that this image has shadows in 2 diff. directions is because how I modeled out the ground plane geometry for the test SPECIFICALLY to see if it would work.. so my ground plane is modeled Up into a square as you see in the image..so that square is casting a shadow FROM the sun.. but in ITS shadow the light reflecting from the building window glass gets to cast a shadows from the ball/boxes Back onto the groundplan shadowed area (the area that is in shadow of the raised groundplane from the sun LOW on the horizon)
I work downton in tampa amogst buildings and this is a phenominon i see daily at sunset.. that a building will reflect the sun and there are these HARD sun rays and shadows in shadows of the buildings going almost in opposite direction from the main light that the sun is casting.. this can really only happen best when the sun is low on the horizon like sunset/sunrise and has glass to reflect the light into shadowed areas

[3dtrialpractice]

That isn't the actual file. I converted it to .jpg from .hdr in photoshop to post it here. It's from a package I bought from Dosch.

-Brodie

hmm.. well dosch makes good hdrs ..
and this hdr IS NOT applied to a geometry sphere right it is acctually set inthe background/illumination channel in maxwell?

ALSO if you are using studio OR plugins.. make sure your PHYSICAL SKY or SKY DOME are not ON by any chance..
cuz there is an option in studio "use instead" that will use physical sky or sky dome to illuminate your scene and only use hdr for reflections..
and in maya plugin.. you can have BOTH the illumination set to sky/dome and also set your hdri to be in background and accidently not hove it set in illumination and you will get render like you posted..

put a BALL in the scene for testing purposes NEXT to yor tree and set the ball to be 0 roughness to give another object test for shadows and to also see if you get hdr reflections on the ball.

Are you using maxwell v2 studio or from PLUGIN?

[Maximus3D]

Oh i understand, so far i never seen that dual shadow effect in real life (i think). Thanks for your explanation 3dtp.

/ Max

[3dtrialpractice]

Oh i understand, so far i never seen that dual shadow effect in real life (i think). Thanks for your explanation 3dtp.

ya its definatly trippy to see.. I'll try to take some photos today at sunset from my window to show real life version.
-luke

[brodie_geers]

Hrm...I tried the HDRI from Maxwell that you mentioned and it seems to be working fine. So it must have something to do with that particular HDRI. I'll have to look into it.

Thanks for the help! I'll post back if I figure anything out.

-Brodie

[3dtrialpractice]

Oh i understand, so far i never seen that dual shadow effect in real life

yo.. I Finally got a chance to shoot an example of this fo shizzle:

the sun is behind me in this pic.. and so im in the shadow but the building in front of me is reflectihng the sun back at me(caustic) and its cusing a second sun effect cuz it has all power of sun light so the colum in front o me is casting a "shadow" in the shadow of the wall behind me..
now if u look im sure youll see this anywher theres metal/glass reflecting the sunset/rise

[brodie_geers]

Funny, a friend just mentioned the other day that he had the weird experience of walking towards the sun with his shadow in front of him (there was a big reflective glass building behind him).

-Brodie

[Richard]

Funny, a friend just mentioned the other day that he had the weird experience of walking towards the sun with his shadow in front of him (there was a big reflective glass building behind him).

-Brodie

Funny I've noticed that I never cast a shadow behind me! Probably because the sun shines out of my a...!

[brodie_geers]

Hrm...that would explain the increase in sun spots lately.


-Brodie

p.s. I'm not sure what that means but it sounds disgusting!

[Richard]

Common phrase here to describe someone who thinks they are pretty cool! They think the sun shines out of their arse!