Thu, Dec 26, 10:18 AM CST

Renderosity Forums / Bryce



Welcome to the Bryce Forum

Forum Moderators: TheBryster

Bryce F.A.Q (Last Updated: 2024 Nov 26 4:28 pm)

[Gallery]     [Tutorials]


THE PLACE FOR ALL THINGS BRYCE - GOT A PROBLEM? YOU'VE COME TO THE RIGHT PLACE


Subject: Simulated HDRI


Kylara ( ) posted Tue, 30 March 2004 at 7:33 AM · edited Thu, 26 December 2024 at 10:16 AM

I always wondered if it would be possible to simulate real HDRI in Bryce (as in simulating that the lighting is actually comming from the HDR-image). So I downloaded a few HDR-images and started experimenting. I think this is very close to how HDRI works for real. In the next few images it's not about the mirrored balls but it's more about the grey ball wich has NO; - ambience - reflection - refraction It's just plain grey with only the diffuse channel used for color. The scene is set up without advanced options (no atmosphere, no blurry reflections, no blurry transmissions and no true ambience). The only thing that's changing all the time is the image I use for the HDRI sphere. Maybe someone has already posted this once but I don't remember then. If so then someone else should be credited for this :)


Kylara ( ) posted Tue, 30 March 2004 at 7:38 AM

file_104136.jpg

See that there's lightspots on the grey ball that's comming from the HDRI sphere


Kylara ( ) posted Tue, 30 March 2004 at 7:38 AM

file_104137.jpg

number 2... See that the pattern of the lightspots on the grey ball is entirely different from the first image


Kylara ( ) posted Tue, 30 March 2004 at 7:41 AM

file_104138.jpg

And here example number 3 Besides the obvious lightspots on the grey ball... Look specifically at the blue floor between the two big balls. That's a spot that could only be hit by the rays comming from the blue point at the HDRI-sphere.


Kylara ( ) posted Tue, 30 March 2004 at 7:48 AM

Thing is... This way it's possible to do other things than just mirrored balls. Instead you can basically take whatever material you want and the lighting still looks natural. Also no problem in adding an extra light somewhere (even if that lightsource should possibly be explained as it is not part of the HDRI sphere then.


Aldaron ( ) posted Tue, 30 March 2004 at 9:02 AM

Nice images. Just FYI, do a search on the forum, you'll find quite a few threads on this subject.


Kylara ( ) posted Tue, 30 March 2004 at 9:07 AM

yes.. but they're not about actually using the HDRI-sphere as lightsource. These images ain't that good but they're just meant to show something.


drawbridgep ( ) posted Tue, 30 March 2004 at 11:12 AM

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=536329

I'm trying to understand. How do you set the HDRI sphere to be a light source? The light is coming from lights, no? I'm trying to see why this is different to the hundreds of HDRI examples in the forum? Maybe a screen shot of your Bryce screen would help me see how you've set this up? I've attached an old picture I did that had a fake HDRI sphere and a ring of lights, but the illumination came from the lights not the sphere. I'd love to know how to get the sphere to be the light source.

---------
Phillip Drawbridge
Website 
Facebook


Kylara ( ) posted Tue, 30 March 2004 at 2:48 PM

The light is coming from lights of course.. but the HDRI sphere is filtering everything to the right colors. This mkes it effectively coloring the lights from the right position. Specially at the lowest image you should be able to see that there's a lot of difference in colloring. ALL the lights are plain white though. And the ball is grey. So the colors on the ball are comming from the HDRI sphere. So yes... this is almost the same as true HDRI. Only thing you have to do is to make the white lights go through the sphere and let the sphere filter out the unwanted colors. It's basically the same principal. Only difference is that the image is set to color the lights here (whatever color the sphere is) instead of being a lightsource itself. The results can be exactly the same though.


drawbridgep ( ) posted Tue, 30 March 2004 at 2:53 PM

AH, So your lights are outside of the HDRI sphere and filter through the sphere, picking up the colour which then hits the objects? Rather than the other way of putting the lights inside the sphere?

---------
Phillip Drawbridge
Website 
Facebook


Kylara ( ) posted Tue, 30 March 2004 at 2:56 PM

Exactly... I have the sphere set at a tranparency of only 2 (so I keep the contrast). Then I use a lightdome outside of the sphere that with fairly intense light settings (intensity of 10 for each light is rather high if it had not gone through an almost black sphere). Now you see that the sphere is coloring the objects you place inside. So this technique makes it possible to use whatever material you want and still get the exact right results.


Kylara ( ) posted Tue, 30 March 2004 at 2:58 PM

And yes... I know it's not a very artistic image... Just made to show how I did it. I thought it was something new but I guess not :)


diolma ( ) posted Tue, 30 March 2004 at 3:11 PM

Well, it's a new technique to me..:-)) Thanks! Cheers Diolma



drawbridgep ( ) posted Tue, 30 March 2004 at 3:15 PM

New to me too. I always put the lights inside. But it's so obvious to put them outside. I think I'm having a... wait for it... yes, there it is... an epiphany. Off to play with this new technique.

---------
Phillip Drawbridge
Website 
Facebook


Kylara ( ) posted Tue, 30 March 2004 at 3:25 PM

Attached Link: http://www.renderosity.com/viewed.ez?galleryid=454337&Start=1&Artist=Kylara&ByArtist=Yes

At the link there's an example of the first time I tried this. Only then I used it to simulate shadows from the trees on sand instead of making use of the sphere itself for lighting. There was still a light inside the sphere then.


PJF ( ) posted Tue, 30 March 2004 at 3:55 PM

Top tip, Kylara! With a sufficiently dense lightdome, this should look extremely impressive.


shadowdragonlord ( ) posted Tue, 30 March 2004 at 7:47 PM

Aye, very interesting technique! I admit it took a bit for me to follow you on it, kylara, but this is good stuff... Especially considering there are no advanced render options turned on, and the render time is just a function of how many lights! Good stuff!


Kylara ( ) posted Tue, 30 March 2004 at 11:16 PM

PJF.. that's right.. My lightdome was not very dense (101 lights). I think when I add another 100 lights it should solve the shadowproblems that are obviously still there. Another option would be to use soft shadows but with 100 lights I'm not too keen on that


AgentSmith ( ) posted Wed, 31 March 2004 at 3:19 AM

Stumbled upon lighting a scene with a picture texture `bout a year and a half ago, I still use it from time to time.

With my version I don't use any lights or the sun, the picture texture creates/drives the "light" all on its own. Some links to my stuff;

Pic 1
Pic 2
Pic 3
Forum - Discussion
Forum - How I do it

AgentSmith

Contact Me | Gallery | Freestuff | IMDB Credits | Personal Site
"I want to be what I was when I wanted to be what I am now"


shadowdragonlord ( ) posted Wed, 31 March 2004 at 10:00 AM

Aye, Kylara, but with Soft Shadows enabled, you could probably get away with 5 or 10 lights, instead. You wouldn't have to rely on light position variance to drive the shadows into submission... Thanks, AS, for all these links. GOod stuff...


PJF ( ) posted Thu, 01 April 2004 at 3:42 PM

With only five or ten lights, Kylara's technique wouldn't work. There needs to be a complete light dome around the spherical 'HDRI' image in order for the colour and luminosity levels in the image to correctly affect the lighting.


Kylara ( ) posted Thu, 01 April 2004 at 11:52 PM

yup... But when I use spotlights I can safe myself a whole lot of rendertime. I'm rendering one now with advanced renderoptions and DOF on. It's going faster than I imagined coz I started it at work to render over the weekend but I saw it's already finished. The shadow problem is cmopletely gone in that one.


shadowdragonlord ( ) posted Fri, 02 April 2004 at 1:31 AM

Aye, I see what you're saying and agree with you, PJF. I was only thinking of the shadow effects themselves... Good point, both of you!


Privacy Notice

This site uses cookies to deliver the best experience. Our own cookies make user accounts and other features possible. Third-party cookies are used to display relevant ads and to analyze how Renderosity is used. By using our site, you acknowledge that you have read and understood our Terms of Service, including our Cookie Policy and our Privacy Policy.