This is rework from some art I created sometime back but have made some changes. The lighthouse I created in Hexagon and then textured it in Bryce. The light is a cone with high ambiance. The terrain is the new Dry grass, moss and stone by David Brinnen in the
Material X-Change. Nope not trying to win kudos just wanted to see how it looked.
The only main light in this scene is the sun along with the light in the light tower and the cone. There is also a radial light in the tower shinning in the window.
Alot to say this time so please bear with me. You seem very genuine so please accept my critique with a few grains of salt. You are taking risks which is excellent. I want to offer you some suggetions before you go off in a direction that will not benefit you
Intersting color choices. I really like the design of the lighthouse itself. Nice work in Hexagon!
I do recognize a couple of major issues in lighting I want to point out. From your desciption you did not use IBL? If you used IBl you need to lower the diffusion of the white textures, They should appear no brighter than greyish. But it you did not use ibl then there is another issue. I feel like the lighthouse is glowing of ambient Renderman. This is no small detail but a big issue. The white seems far too white for the environment which is dark, dark water, dark sky, dark landscape. Where is all that brightness supposedly coming from? The lightouse should be almost invisible in the darkness, not bright white. Remember that the true meaning of ambient is that it is the dim left over light from the enviroment, not some alien force of its own. If the sky is black then there should be almost no ambient light of any kind because the sky is not casting any. In outdoor scenes the sky color is your clue to how bright your ambient lighting should be. If you wanted to provide background light for the lighthouse you should have used low intensity IBL instead of the ambient channel. I'd say this is an example of the problems with the ambient channel. You have to test it to learn its shortcomings. Hopefully you recognize the negative impact the ambeint glow is having. The lighthouse looks like it is in it's own world or context separate from the environment around it, which is very unrealistic. I did suggest you play around with ambient glow for 2d sky backgrounds but not in cases like this. Ambient glow in general only applies to items that are meant to appear to be thousands of degrees in temperature. Hot stuff. Ambient glow equals heat! The ambient glow of the white throws off the temperature reading of the scene making it too warm. Is the lighthouse possesed with a poltergiest? If not then it should not be glowing this way. Call the ghostbusters!
The water is awesome, it has just that hint of transparency that is needed. Alot of users cheat water with a highly reflective silver. Water does have reflection but it has many other properties also. Silver is a nice "shortcut" but real water needs transparency more than reflection. Great job.
As I consider the image, I wonder if you'd be willing to try the scene again with a couple of different lighting choices. First, remove all ambient glow from the tower and the boat sails. Second, make sure that the Sky dome color is set to full black. Skydome is another "ambient like" trick. It is false and unreal. It is a lie. A Skydome should cast light from all angles like the word "dome" implies but in Bryce the skydome is actualy a large spotlight shining straight down only and not offering any light from the sides. The only true skydome in Bryce is the IBL feature. You could also build your own dome of radials for the same effects. IBL is your replacement for the ambient channel and the sky dome effect!
To maximize the potential of the set up I offer these suggestions. 1. remove all ambeint glow from all textures. If you are afraid the models will not be visible in this low light just remember that ambient glow is never the answer. Real lightsources are the only way to go, just make them dark colored and dim. Just place a few weak radials around to light the models, You can hardly go wrong. I would suggest removing the bryce sun altogether. The scene should feel like a sunset or sunrise or even late night time. Lower the sun to about 10 degrees or remove it completely. The only light you need other than the lights inside the top of the lighthouse, is Horo's moonbluegrey hdri at a low intensity, do not let it get too bright. This will give you that realsitic ambient liighting your instincts are expecting. Afterall Horo made it based upon images he shot of the moon at night time! The haze color is not right. First I do not understand why you chose yellow, but moreso, be careful of horizon brightness levels. You can link horizon to sun and all. Just make sure that the sky color is complimented by the haze, and not contradicted by it. You need amuch darker haze color. Also, use Frozencry's Streaming lights from the mat exchange as the beams from the lighthouse. It will give the appearance of interference.
I said alot here I hope I did not seem harsh. My main point is that ambient glow was not the best option if you want a plausible result. Do not take a step backward in your skills training so to speak by putting ambient glow in all the wrong places. Applying ambient glow to room temperature objects is a very bad habit many users suffer from. Even an ambient glow setting of 2 is too much. You do not need any ambient glow at all if you use real lightsources. What many users don't undertand or accept is that with a few weak radials they can accomplish much better ambient lighting than the ambient channel provides. Later bud!
Join Date: 11.10.2007 Comments: 358
I thought I would reply right away so you don't think I am having a fit ha. I did not even think about the ambiance in all the materials in the boats and the lighthouse as I added mats to these items sometime back. But thanks for the reminder I am checking them right now and you are right many of the mats have ambient added to them. I will have to select each item and change it.
I am reading your post over and you did say allot ha. But that is not a problem I appreciate you taking the time to share with me. Some great suggestions I will see what I can do. I did notice that ambient washes out the colors in some cases.
I still have not found Horo's hdri's that are mentioned are they in the materials exchange?
I was looking for a good tutorial on light beams but could not find one for my application so I will check out Frozencry's as you mentioned.
Thanks for your comments.
Join Date: 05.26.2004 Comments: 4571
What you have and I have not, RenderMan, is a great feeling for art. The composition and the colours are just great - not realistic at all, mind you, but artistically very appealing - down to the yellow horizon.
Rashad always goes on about ambiance and, to tell the truth, in the beginning, it was quite unnerving to me. Meanwhile, however, I appreciate his verve about this very much, because he is simply dead right and a lot of Brycers haven't realised yet how wrong the ambience setting can be. Since I set the ambiance channel to 0 and the skydome to black, the look of my pictures has grately improved (and de-selected Gamma Correction in the Render Options menu). Ambiance is the choice for glowing materials like lightrays, fires and the likes. Bryce always sets ambience to 19.6 or so, which gives bright objects that look - as Rashad rightly says, cartoonish. If you get objects over from DAZ Studio, the most annoying work is usually to select each mesh separately and remove that @*#% ambiance.
The MoonBlueGrey HDRI Rashad mentiones can be found on my website www.horo.ch. Go to Raytracing > Resources > HDRI > Page 3 - near the end of the page. This HDRI gives excellent ambient light. That this is so is partly pure accident and partly the result of recommendations by David, who tested and used it on many renders.
Join Date: 06.04.2006 Comments: 2622
Ha ha! Thanks for the back-up Horo. As I review previous posts I've made I do indeed go on at length about ambient, perhaps too much. Never have much good to say about it. I had the feeling I was probably unnerving people with my zeal. Sometimes my passion does get the best of me, I am the first to admit. You are always patient with me and I do appreciate that. I am glad though that even you have recognized the benefits of avoiding ambient glow.
The shortcomings of the ambient channel and the skydome were well known to me. But you mention gamma correction also. I am testing it out now and I think you are right on! The entire color scheme changes drastically. If you might be willing to explain the concept of what gamma correction is and what are its benefits and drawbacks? Thanks again.
Join Date: 11.10.2007 Comments: 358
Horo that was very nice comment and thanks for the MoonBlueGrey download. I spent some time on you site looking for these hdri's that everyone was talking about but could never find them. So Rashad was asking me to make bricks without straw. Ha
OK OK OK Rashad I am a believer but the question is were do I go from here.? You took away my ambient and in this case my sunshine so now what I am to do? I am like a boat without chart or compass. I am going to need a lighthouse very soon so really need to finish this one. This all happened after I read your term paper on ambient light Ha (blame shifting)
I removed all ambient from all materials except the light cone and added the special affect as mentioned but I ran into many difficulties. First of all I did not have the specialized hdri that was mentioned until now so I tried several of the hdri's on my computer and used them with some success. I had every thing from flat ocean water to not being able to see the water at all. Then if I turned up the ambient light the terrain was to bright but the ocean looked great so I added some noise to the terrain and ended up with spikes(yes I know better) . Then through all my trial and error I lost the light in my nice beam of light but found out that in my zeal I turned off the shadow intensity or made it black in the sky pallet. Should I mention that the sails never had any ambient channel added. It was the reflection and to much diffusion.
I might also add that I tried to make my own sun with radials lights but they just don't seem to make a good sunset or sunrise. Then I added radials lights in different locations to make the water look real but then the terrain would be to light. Did I also mention that I have rendered this scene about 10 times since I receive you comments on ambient lighting.
Well I could ramble on and on but for now I might need some suggestions unless the MoonBlueGrey is the answer to all my life"s problems.
This is all said in good sport but really have had some problems without my sunshine. I really won't miss the ambient in the materials on objects but would like to know some good ways to brighten up my night scene. I will start with the MoonBlueGrey and then try some more radial light affects and being waiting for some suggestions.
I am going to take a short break from this but will post my best outcome in the Work in Progress so I can get some suggestions. Thanks
Join Date: 06.04.2006 Comments: 2622
Thanks for understanding that my comments were meant in the most positive sense. Thanks also for taking my advice and applying it to the scenario.
To be honest, you have chosen a very challenging subject. The extremity of the atmospheric settings makes it tough. But you can surely achieve greatness with this scene. The secret to this scene is the indirect light. There is little influence of the direct sun. Horo's hdri will provide almost all of the light you need in this scene. I think you could light the scene exclusively with the hdri at a low intensity setting. The enviroment has to appear dark enough to make the Lighthouse a necessary feature. As I think about it this scene is not so different than your What a View scenario. Night time is very challenging and if you look at my personal gallery you will not find many attempts made by me.
Yes I agree, no one really misses the ambient channel once they let it go. The default sun on the other hand is frustrating to abandon because something as simple as sunlight should work reliably from the box. To need to rig sunlight in a landscaping program seems at first quite ridiculous.
Once you accept that the bryce sun needs replacing you then just need to solve for how you are going to place your sunlight. You will always need to keep your sun effect visible in the skylab even when you disable the sunlight itself. The sun drawn onto the sky will be a dummy effect merely to indicate where the sunlight provided by your invisible radial is supposedly coming from. Radials were never intended to replace the sunlight effect drawn onto the sky. The radial is meant to simply provide the light. You just need to create a sunlight rig that can be animated in accordance to the positions of the bryce sun effect drawn onto the sky. If you would like I can e-mail you a sunlight rig that has worked reliably for me.
Steps are as follows:
Note: If you use the director camera mode like I do you must make sure that the camera remains centered as you place distant objects. The director camera rotates on a point that is a triangulation of the center of all of the models in a scene. As you place objects far away the camera begins to swing wildly and it is frustrating. You must stabilize the camera by creating a sphere , making it a hidden, and giving it a size of 102400 along all 3 axis. This will give you an invisible sphere that is large enough to extend farther than most models you would place in the scene, even your replacement sunlight. This will stablilize the camera perfectly.
1. Create a radial lightsource. Give it a fall-off of "none" so that the light contiunes at a consistent intensity forever. Make it a strength of about 15 with a slightly reddish or orange tint. Do not oversaturate the light color. This is a good brightness for a direct sunlight in most cases. You might need to lower diffusion levels of some materials under this bright light.
2. Enlarge the radial light to 5000x5000x5000. In the object attributes make sure it is centered along all axis and zeroed out along all rotation parameters.
3. Place this light source as far away as possible by entering the number +40,000 along the Z axis.
4. Now you need to create a plain sphere and place it at true world center just like you had placed the radial originally. Give this sphere the name "sundial" and make it "hidden" in the object attributes.
5. Now select our distant and very large radial light from out there. In the object attributes you will see a screen for linking. When you open the link dialogue click on to "sundial." Make sure all 4 red checkmarks are activated indicating the link status modes. Close the dialogue.
6. Now you have a bright sunlight sitting at the horizon far away and it is linked to the sundial at the world center. Now go to the sky lab and set the sun position to 0 azimuth and 0 altitude. Make sure the sun effect is visible. Disable sunlight and disable Link sun to view.
7. What you should observe now is that the sunlight effect drawn onto the sky aligns perfectly with the radial light positioned far away. You should make sure that these two remain aligned at all times.
To maintain alignment of the drawn effect and the true light providing radial you need to make sure you always numerically enter your sunlight postions in the sky lab because you will need to translate those exact numbers into rotation information for your sundial. In general the Azimuth setting in the sky lab will align with the sundial along the Y axis. The Altitude setting in the sky lab will align with the X axis. The azimuth information enters exactly the same but when entering altitude you will need to represent the factor as a negative along the x axis. For example you will want a setting similar to this for your scene. rough example : azimuth 45 altitude 4. This is a very low altitude sun and bryce should give you some nice redding of the sky color and the haze at this setting. Now align your sundial as follows: X= -4, Y= 45, Z= 0.
8. Due to the linking you can adjust the rotation of the sundial to move your sunlight around as needed to match any time of the day or skyklab position. Sunlight is solved. I suggest aligning the hdri also. It could be good in this case.
Another long entry. I hope I addressed your questions adequately.
Join Date: 05.26.2004 Comments: 4571
I have again problems entering a comment. It says "Please add a comment" and my comment is deleted. This happens now and then, no idea what's going on. Here's another try.
The gamma correction is ON by default and I've found out about it by one of David's comments a long while ago (the render speed test file "Bosta" still has gamma correction on, I didn't know then). It is like ambient in the sense that it gives the novice a pleasing result without bothering too much about bright light and black shadows. Gamma correction is softening contrast and makes every picture look the same.
The rational behind gamma correction is that the human eye does not perceive light linearly, but in some sort of a logarithmic fashion. The sensitivity of chemical film acts to light coincidentaly and conveniently rather like the eye. Digital cameras with CCD chips (CMOS are logarithimic) and also display units treat light physically correct as linear and thus things have to be corrected for the human eye. Nothing wrong about this.
Now if you use gamma correction for a render, you correct twice and that is definitely overdoing it. A better way is rendering without the correction and adjust contrast, if necessary, with a graphics application because you know and see what you are doing. It is the centre slider, having it at 1.00 means no correction. By the way, Windows machines use a gamma of 2.2 for the display correction while Mac uses 1.8.
I have the curve of the Bryce camera with and without gamma correction on my website: Raytracing > IBL/HDRI? > 5. Gamma. (The curve for my DSLR camera is wrong, a greyscale HDRI is needed. No problem for the Bryce camera, though, because it is perfect.)
Compare your scenes rendered with gamma correction engaged and without. You may discover why some lights you've positioned do not give the lighting effect you've (rightly) anticipated.
Bryce treats HDRIs correctly with a gamma of 1 (i.e. no correction) for the light it generates. However, if you render it as background, you'll discover that colours are saturated and contrast is high. It looks discusting and this is not only because of low resolution. The best Bryce can handle is a 6400 pixel diameter HDRI and if the camera FOV does not exceed 60?, you get a crisp backdrop - which still looks ugly. Here, a simple gamma correction slider would be more helpful than a 12 slider tone-mapper. Not that DAZ was not made aware of that during development of the IBL feature.
RenderMan - I disagree with Rashad in using the Directors camera. Reality is to move the camera, not the landscape. I use the free moving camera set at X/Y/Z = 0 (sometimes at Z=-100) and all rotation angles at 0 to start with. I think this makes life a lot easier when placing objects - though it is not "righter" than using the directors camera. I've also never noticed the free camera wobbling around.
Join Date: 06.04.2006 Comments: 2622
Thank you Horo for your explanation. I have been testing it out and you are certainly correct. I had been dumbfounded as to why after careful consideration of each facet of an hdri, I still was having to adjust contrast in post. I was not getting 100% reliable colors. My estimations were always off an no matter what I did I could never compensate. With gamma correction off now every color turns out like it expect it to. I'm very thankful for this piece of the puzzle. It seems to have no negative impact on render time which is a major plus.
You are also right Horo in that the director camera perhaps is not the most natural. I will try working more with the Camera View to see what happens. Your suggestions are always good.
Join Date: 11.10.2007 Comments: 358
I have read both of your comments over a couple of times. First of all I always use Camera View and then use the Director Camera to check things and sometimes to move lights or make sure objects are landed but do all my rendering in Camera View. It could be this was a habit that I learned with Carrara. I have never checked my camera settings I just find something I like, but will check this feature out.
I was wondering about how big you can make a radial light so this question has been answered. But what about what David mentions in his tutorial on his web page about placing a radial light in front of the sun? Would this work also for a night scene and is there a way to link the radial to the real sun in Bryce? I understand what you are saying about linking the radial to the hidden sphere as this will keep the radial aiming to dead center. At least this is my understanding.
I would not mind you emailing me your rig I am sure
I could give you my email through private messaging at Daz or NightStar or Horo might be able to give it to you. Let me know. Thanks for the offer.
Horo I can follow you most of the time but you have breached a topic that I am not familiar with. I know there is a gamma correction in post processing but I hardly ever use it. I have tried it before but did not like the results. It this the gamma that is checked by default that you are talking about? I never noticed if this was on by default every time I open the Bryce.
What I hear you saying is that there is some gamma correction in hdri and then to have the gamma correction turned on will cause a double correction. It this also true if you are not using the hdri? Or is it always better to us another application for the gamma correction? As mentioned so you have more control using an outside application and don't have to be surprised after a long render.
I will try the large radial for this scene as mentioned. But Rashad you are right it is tricky I would like the water to stay just as it is in my picture above but would like to darken the rest of the scene and still have a dynamic backdrop. I am asking alllot but this is what I see in my mind but don't know how to get there. I tried at one point placing the radial lights in the water and this still has some possibilities, but again I could be just dreaming.
Thanks again for taking the time to share ideas. It is nice to know that we are entering into almost uncartered whoops uncharted areas when it comes to dark scenes.
Join Date: 05.26.2004 Comments: 4571
Gamma on rendering is on by default and it "corrects" the resulting 2D picture in a way you have no control over. Therefore, applying gamma corrction - if any - is better done in post production.
HDRI is a different thing and I better had not mentioned it above because this only confuses. A HDRI backdrop will also be gamma corrected while rendering if the option is enabled.
However, a HDRI as backdrop almost always looks over saturated and this is because the light of the HDRI and the picture of the HDRI are treated the same way in Bryce as far as gamma correction is concerned. To display the HDRI properly as background, it has to be converted to an LDRI and this conversion needs some tone-mapping operators of which gamma (or pre-gamma) is the most effective.
If you have certain preferences of how the settings should be when you start Bryce, you can configure this. This is easy. Just open a new scene, adjust camera, gamma correction TIR, Sky, Sun position, ..., then save this scene as "default.br6" into the folder of the Bryce main program. This file is always loaded when starting up Bryce und everything is already set the way you want it without the need to bother whether you have some option to switch on or off. This, you will do later in the work when necessary.
I try to keep things short here. Perhaps we should use the forum for such discussions, or - as you suggest - email.