Stoner opened this issue on Apr 28, 2006 · 52 posts
Stoner posted Fri, 28 April 2006 at 1:29 AM
I finally got to ask this question. What is fake HDRI, and how do you achieve this effect? Is it the same thing as lightdomes and fake radiosity?
Good spelling is overaytead
CrazyDawg posted Fri, 28 April 2006 at 2:16 AM
Attached Link: http://67.15.36.49/team/Tutorials/faking_hdri/faking_hdri.asp
No doubt i'll get jumped on for this..in a good way.Fake HDRI is using lighting in images/renders to make it look more realistic. Look at the link i posted its a good tutorial on how to use fake HDRI. there are other tutorials around.
I have opinions of my own -- strong
opinions -- but I don't always agree with them.
AgentSmith posted Fri, 28 April 2006 at 2:45 AM
Unfortunately, that tutorial won't translate into Bryce.
I started doing the workaround for HDRI I think about 4 years ago now, silly of me never to have posted up a proper tutorial here......
Simplest way to describe how to do this in Bryce;
Take your Bryce scene, create a sphere, make the sphere big. Place a real world photograph on the sphere.
Now anything that is inside of the Sphere will reflect that photo, and there you have it. It also affects transparency and refraction.
There is obviously more to this, as far as mat lab settings, but basically that is it.
I'll go find some of my old notes, and put something together, once and for all, lol
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AgentSmith posted Fri, 28 April 2006 at 2:50 AM
Some of my old posts;
This one shows my settings for the sphere, which is key;
http://market.renderosity.com/mod/forumpro/showthread.php?thread_id=1775481
Shows a cutaway;
http://market.renderosity.com/mod/forumpro/showthread.php?thread_id=1716309
VERY unfortunately these old posts still have that PHP swichover problem of images being replicated everywhere, but you should get the idea.
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CrazyDawg posted Fri, 28 April 2006 at 3:06 AM
See told you someone would jump on me, never thought it would be AS with his size 13 boots. :tongue1:
PS: AS i have no problem seeing those images on either of those links you posted..
I have opinions of my own -- strong
opinions -- but I don't always agree with them.
AgentSmith posted Fri, 28 April 2006 at 3:17 AM
Lol...nah. The MOST important thing is the special kind of image to put on the sphere and you link gave that! (fyi for anyone - you wrap it spherically onto a sphere, btw...I know, sounds logical, but most people miss it the first time around)
Oh, you can see the images in those posts, no problem...but there shouldn't be some sort of image in almost every post in those threads. It was a glitch that happened in the switch over, and it obviously has not/cannot be fixed.
Quite irratating and unfortunate.
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CrazyDawg posted Fri, 28 April 2006 at 3:32 AM
well once i get this hexagon 2 downloaded and am able to re-download bryce i'm going to give HDRI a go on a few objects..it looks great and it gives ones imagination plenty to work with..
New form of 3d art Fake HDRI with a twist :)
I have opinions of my own -- strong
opinions -- but I don't always agree with them.
Stoner posted Fri, 28 April 2006 at 6:06 AM
Thanks for the enlightenment
Good spelling is overaytead
Erlik posted Fri, 28 April 2006 at 6:07 AM
Quote - Take your Bryce scene, create a sphere, make the sphere big. Place a real world photograph on the sphere.
Now anything that is inside of the Sphere will reflect that photo, and there you have it. It also affects transparency and refraction.
You can get better results if you play with the Ambience of the sphere photo. Sometimes you need to up the Ambience quite high for the objects in the scene to reflect anything. Put the image in the Ambient channel, too, like AS did. If you don't use Ambient/Ambience, you have to put a radial light that will light up the sphere. And then you can have a problem with the specular reflections from that light. IIRC, my Art of War used a reflection sphere with the Ambience on high.
-- erlik
tjohn posted Fri, 28 April 2006 at 3:11 PM
Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1004957
Also you might want to shut off all the shadows options in the material editor for your fake hdri sphere, especially if you want to use the Bryce sun to illuminate your scene. And did anyone mention that your camera has to be inside the sphere?If you're familiar with my "close up" object work, I use this technique to make the textures look more realistic. The link is an example. The lighting effects on the green surface are a reflection of the hdri sphere, the texture has a very tiny bump map that breaks up the image. I usually add a small bit of reflection to any object that would have even a tiny bit of reflection in the real world.
Almost any picture will work for the fake hdri effect, unless you want a mirror type reflection on some objects, then you'll want to use a hi-res image for your hdri sphere.
It really is a fun technique. Good luck with it!
This is not my "second childhood". I'm not finished with the first one yet.
Time flies like an arrow; fruit flies like a banana.
"I'd like to die peacefully in my sleep like my grandfather....not screaming in terror like the passengers on his bus." - Jack Handy
RodsArt posted Fri, 28 April 2006 at 5:57 PM
On the Sams bicycle, I used a mat the looks like a view from inside a factory. No transparency, just a light dome inside, reflective floor. The twist on this one is, I made a mask for Photoshop to separate the bike from it's enviroment, then applied a lens blur to the background using a gradient channel....thus giving the DOF only to the reflective floor and background.
Lots of fun....experiment!!
ICM
p.s.
The floor of the factory is brighter due to the light dome being closer to the ceiling and not the walls of the sphere.
p.s.2
The Red shiny mats are both...AgentSmith's carpaint material with slight variations for enviroment.
___
Ockham's razor- It's that simple
artnik posted Fri, 28 April 2006 at 6:09 PM
bookmark
Erlik posted Fri, 28 April 2006 at 6:24 PM
Quote - Transparency allows the Bryce sun to illuminate the sunny spot in the clouds on the Mat.
Just use a greyscale version of the HDRi photo for the transparency map of the sphere. You can play with the levels in photoshop to get the areas between the clouds to be darker and thus more transparent. Or invert the pic, if the clouds are really dark.
-- erlik
AgentSmith posted Fri, 28 April 2006 at 6:37 PM
Some other settings I use myself;
Placing beads beside "Transparent" & "Transparency" underneath the column where your sphere image is, (i.e; Channel A) will allow the image to be transparent to let your sunlight through, but also color that sunlight as a lighting gel would.
*Notes;
-Your image should be inverted in the middle, "Alpha Image" box in your Picture Lab.
-The "Material Options" should be set to Normal.
-I normally set my Diffusion to 100 & my Ambient to 15, as a default. Then I might tweak those to get the reflections in my scene to my liking.
-If the scene appears too dark, I will de-activate the "Cast Shadows", in the Material Options of the sphere. I always deactivate the "Recieve Shadows", and "Self Shadows".
These are the settings I have used in just about every one of my LDRI images. (Low Dynamic Range Image), which is what a jpg is.
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xenic101 posted Fri, 28 April 2006 at 9:55 PM
CrazyDawg posted Fri, 28 April 2006 at 10:01 PM
@ICM thank you for reminding me of another mat i had and need to get once again.
@AS where can i get you red car paint mat from again..
oh god i hate having to do this all over again
I have opinions of my own -- strong
opinions -- but I don't always agree with them.
Quest posted Fri, 28 April 2006 at 10:02 PM
These are effects tricks that were in existence in 3D packages years before the HDRI acronym came into casual use. The effect lacks in that in real HRDI actual luminance values are used to enhance the effect. Something which faking it doesn’t come nearly as close to doing. Even further, only certain video devices can actually demonstrate the full effect. Something tantamount to High Definition TV as compared to regular TV. But untrained eyes would certainly view a difference since the whole of a 3D object’s environment is reflected from it’s surface. As has been said, playing with ambience and shadows can enhance the effect.
AgentSmith posted Fri, 28 April 2006 at 10:17 PM
Yup, Like quest says, before HDRI was "reflection mapping". And also yes, Bryce can't do the "High" part which is 48-bit rgb color, but you get the main desired effect; more realistic looking reflections, transparencies and refractions.
Car Paint;
http://backroom.renderosity.com/~bryce/paintedmetalbase.zip
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CrazyDawg posted Fri, 28 April 2006 at 10:22 PM
thank you AS..
I have opinions of my own -- strong
opinions -- but I don't always agree with them.
Quest posted Fri, 28 April 2006 at 10:46 PM
Attached Link: http://en.wikipedia.org/wiki/HDRI
Here's some more infomation on HDRI:Stoner posted Sat, 29 April 2006 at 1:34 AM
Ok, I think I have enough now. So much fun lying ahead, and so little time. Thank you all
Good spelling is overaytead
Stoner posted Sun, 30 April 2006 at 5:30 AM
Good spelling is overaytead
AgentSmith posted Sun, 30 April 2006 at 5:42 AM
That's F-ing Metal!
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tjohn posted Sun, 30 April 2006 at 5:45 AM
Nice...You can see how the technique adds a bit of realism to reflections.
This is not my "second childhood". I'm not finished with the first one yet.
Time flies like an arrow; fruit flies like a banana.
"I'd like to die peacefully in my sleep like my grandfather....not screaming in terror like the passengers on his bus." - Jack Handy
RodsArt posted Sun, 30 April 2006 at 7:02 AM
Super result!!
___
Ockham's razor- It's that simple
FranOnTheEdge posted Mon, 01 May 2006 at 10:27 AM
I just know I'm gonna regret asking this, but I don;t see why there's such a fuss about this mapping an image onto a sphere, business.
I mean all I see reflected is the surface the "heavy metal" block is sitting on. And all I see in the bazzewood image is the surroundings, i.e. the objects that are there next to the ball.
Okay so with the bicycle, you see a roof that isn't really there - that one I get. But with the others, wouldn't you get those reflections anyway, with or without the HDRI thingie?
Please explain to the blind fool over here in the corner.
Measure
your mind's height
by the shade it casts.
Robert Browning (Paracelsus)
Rayraz posted Mon, 01 May 2006 at 10:56 AM
Quote - VERY unfortunately these old posts still have that PHP swichover problem of images being replicated everywhere, but you should get the idea.
Well, I DID say you could've hired me to program this puppy...
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Erlik posted Mon, 01 May 2006 at 1:57 PM
Quote - But with the others, wouldn't you get those reflections anyway, with or without the HDRI thingie?
Er, Fran, take a look at the highlights on the cube. See how many are there? That's from the light/white areas on the sphere. IE, they could be from more windows. Ergo, more realistic. Edit: And you get more highlights without worrying about placing more lights and adjusting their strength and whatnot. BTW, I really would like having "no specular" option on the lights in Bryce.
-- erlik
Stoner posted Tue, 02 May 2006 at 10:26 AM
Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1211154
I´ve posted the final "Heavy metal"-image hereGood spelling is overaytead
FranOnTheEdge posted Tue, 02 May 2006 at 10:27 AM
Quote - Some of my old posts;
This one shows my settings for the sphere, which is key;
http://market.renderosity.com/mod/forumpro/showthread.php?thread_id=1775481
Shows a cutaway;
http://market.renderosity.com/mod/forumpro/showthread.php?thread_id=1716309
VERY unfortunately these old posts still have that PHP swichover problem of images being replicated everywhere, but you should get the idea.
The link with the sphere settings - which you say is key - I simply cannot get to, no matter how I try or whch way around I try to find it, Firefox always crashes - I just cannot get to that thread.
Please, is there any other way to get the information now permanently hidden from me?
Also, is there a site that has images good enough to use for the sphere? (I'm sure there has been links to such stuff, I just dunno where to find it).
Measure
your mind's height
by the shade it casts.
Robert Browning (Paracelsus)
FranOnTheEdge posted Tue, 02 May 2006 at 10:28 AM
Quote - > Quote - But with the others, wouldn't you get those reflections anyway, with or without the HDRI thingie?
Er, Fran, take a look at the highlights on the cube. See how many are there? That's from the light/white areas on the sphere. IE, they could be from more windows. Ergo, more realistic. Edit: And you get more highlights without worrying about placing more lights and adjusting their strength and whatnot. BTW, I really would like having "no specular" option on the lights in Bryce.
I guess I've just gotta try it out myself - to really understand the difference.
Measure
your mind's height
by the shade it casts.
Robert Browning (Paracelsus)
AgentSmith posted Tue, 02 May 2006 at 6:26 PM
Basically (in my mind), it's this;
In real life, imagine a reflective sphere floating above the desert ground, in the middle of nowhere.
That's Bryce's default scene. (with a mirrored sphere) Boring...
Now, in real life, you sit in your livingroom holding a ball bearing. The bearing looks realistic doesn't it? Lol...well, sure it does, it's real life. But, my point is no matter how realistic your Bryce material is...it will not appear as realistic as possible if it cannot have some of the enviroment that a real object does in real life.
And, with reflective objects/materials, the largest missing ingedient in 3D world realism is something to reflect.
And, even more so with glass objects, since in additon to reflection, thay have transparency and refraction.
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FranOnTheEdge posted Mon, 08 May 2006 at 5:53 PM
Hmmm, but putting 'things' in a 'room' with your Bryce made ball bearing won't work? Why not?
And is this why one of the mats I was making showed an odd sort of ring-like reflection, as if reflecting a massive sphere? (I wasn't using one though)
Measure
your mind's height
by the shade it casts.
Robert Browning (Paracelsus)
Quest posted Mon, 08 May 2006 at 8:22 PM
Fran, believe me, the reflectology of the sphere, herein called HDRI (fake), will help to render your scenes more realistic if that’s what you want. Imagine in the 3D world you have created a room and your main character is centered therein holding a highly reflective sphere…the sphere of the future (for argument sake)…but you want this sphere to reflect it’s surroundings as realistic as possible. How could you represent this for the sake of trying to give the illusion in a 2D image of it being a 3D scene? Using HDRI!
AgentSmith posted Tue, 09 May 2006 at 4:35 AM
Hmmm, but putting 'things' in a 'room' with your Bryce made ball bearing won't work? Why not?
-`Course it will, put as much stuff in there as you want. Doesn't have to just be a ball bearing.
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PJF posted Tue, 09 May 2006 at 7:51 AM
Quote - Doesn't have to just be a ball bearing.
I think Fran's puzzlement is regarding the supposed benefit of the ball bearing reflecting the inside of a sphere (with a photograph of a room mapped to it), as opposed to the ball bearing reflecting a room (scene) made in Bryce.
If so, I share that puzzlement. I can see that it might save some modelling time, but I can't see that it's especially relevant to simulating HDRI lighting.
drawbridgep posted Tue, 09 May 2006 at 9:37 AM
Did someone say ball bearings?
Sure, I could have modelled the background in Bryce, but it wouldn't look as real as a photo.
tjohn posted Tue, 09 May 2006 at 11:38 AM
Phil:
Just a red x.
This is not my "second childhood". I'm not finished with the first one yet.
Time flies like an arrow; fruit flies like a banana.
"I'd like to die peacefully in my sleep like my grandfather....not screaming in terror like the passengers on his bus." - Jack Handy
drawbridgep posted Tue, 09 May 2006 at 12:06 PM
That's what comes from trying to be clever (and the forum being on a different server to the gallery)
Try that instead.
tjohn posted Tue, 09 May 2006 at 12:24 PM
Now the other one is showing, too. Weird.
This is not my "second childhood". I'm not finished with the first one yet.
Time flies like an arrow; fruit flies like a banana.
"I'd like to die peacefully in my sleep like my grandfather....not screaming in terror like the passengers on his bus." - Jack Handy
Erlik posted Tue, 09 May 2006 at 3:42 PM
I see both, too. They both have the same link. Phil, in Bryce you'd have to model a panorama. And then play with spherical mapping... PS. Phil, you've apparently got a following. But don't you find it a little disconcerting that people can say "great idea!" for something that's a test? You've got a tons of real great ideas...
-- erlik
drawbridgep posted Tue, 09 May 2006 at 3:58 PM
I have a following? I wish they'd donate money to me.
I'd rather they "great idea:, than say, "give up and try knitting", at least I knew that I was on the right track. :-)
Vile posted Fri, 12 May 2006 at 6:57 PM
That is cool metal I like faking it errr in Bryce that is!
FranOnTheEdge posted Sat, 13 May 2006 at 7:14 PM
Quote - > Quote - Doesn't have to just be a ball bearing.
I think Fran's puzzlement is regarding the supposed benefit of the ball bearing reflecting the inside of a sphere (with a photograph of a room mapped to it), as opposed to the ball bearing reflecting a room (scene) made in Bryce.
If so, I share that puzzlement. I can see that it might save some modelling time, but I can't see that it's especially relevant to simulating HDRI lighting.
Exactly!
Measure
your mind's height
by the shade it casts.
Robert Browning (Paracelsus)
AgentSmith posted Mon, 15 May 2006 at 3:35 AM
Oh, sure, absloutely.
BUT...you would have to build up a realistic looking world/room/scene around the objects for it to reflect something realistic, a photograph gives you a very quick leg up.
I have seen reflective spheres scenes with a nice bryce-built realistic enviroment, was very impressive.
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RobertJ posted Mon, 15 May 2006 at 4:48 AM
Attached Link: http://www.renderosity.com/viewed.ez?galleryid=1219606&Start=1&Sectionid=2&filter_genre_id=0&WhatsNew=Yes
My latest piece is nice example of a fake HDRI, much quicker and far more satisfying result than i would achieve with Bryce alone.And yes, the robot is completely booleans and such.
Robert van der Veeke Basugasubasubasu Basugasubakuhaku Gasubakuhakuhaku!! "Better is the enemy of good enough." Dr. Mikoyan of the Mikoyan Gurevich Design Bureau.
AgentSmith posted Mon, 15 May 2006 at 5:15 AM
That robot f-ing rocks, pure & simple.
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Gog posted Mon, 15 May 2006 at 6:19 AM
The big thing about HDRI is the R i.e. 'Range'. using an HDRI image means that there is more detail thats lost in an LDRI image (ok I'm talk the obvious bit here - BUT what's the impact of this)
the LDRI image will offset it's colour range according to the average colours in the image, losing details either in shadow or light areas or both. So when using LDRI images you will lose details of th light 'blooms' say for exampke you have a grid covered light as the light source, in the HDRI image you'll see the subtle gridding in the light blooms that this would cause, the LDRI image is likely to wash out this detail, or at the other end of the scale - the dog at the back of the kennel resting out of the sun - in an LDRI image the shadow will lose the detail and you'll just see a dark shadow and not the dog lurking within.
The impact becomes most noticeable where real life situations would emphasize the difference, for example the caustics from a glass of water would emphasize the gridding by way of creating a diffraction pattern based on the frequency of the grid, (it'd actually be the cross of a refraction and diffraction pattern but I didn't want to get too techy) guess what you're gonna lose it LDRI (not that bryce does caustics anyway or that many prorgrams could create caustics based on an HDRI as photon emitter......)
----------
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Erlik posted Mon, 15 May 2006 at 6:19 AM
Ditto AS!
-- erlik
TwistedBolt posted Tue, 16 May 2006 at 7:57 PM
Its not really faking HDRI, a high dynamic range image cannot be faked. What everyone is doing, is using a "skybox"( or sphere in these cases).
I eat babies.
RobertJ posted Tue, 16 May 2006 at 11:14 PM
Yes it is a skybox and we make the lighting, ambient lighting and such fix the skybox, call it what you will, i will still call it a fake-HDRI.
Party pooper.
Robert van der Veeke Basugasubasubasu Basugasubakuhaku Gasubakuhakuhaku!! "Better is the enemy of good enough." Dr. Mikoyan of the Mikoyan Gurevich Design Bureau.
TwistedBolt posted Tue, 23 May 2006 at 12:27 AM
Lol,sorry... awesome avatar btw.
I eat babies.