Rashad's Thoughts on Lighting in Bryce 7.1 Pro in 2017

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  • Rashad CarterRashad Carter Posts: 1,799

    Blend Transparency-

    Blend Transparency is evil! Yep, I'll say it! Just like Ambience, Blend Transparency presents itself as the proper solution to many problems but it comes at steep but hidden costs. I'll remove the veil

    When using less advanced methods of lighting such as just the sun and some Ambience glow, the slow down of Blend Transparent surfaces remains difficult to observe. But as soon as you start using more adanved methods like TA, IBL. EGDLS you learn that Blend Transparency is the slowest material setting found in Bryce.

    The issue is once again, SHADOWS

    Why are shadows so costly in so many situations? Simple. Though light rays usually are emitted from infinitely small points in space, shadow rays by comparison are exchanged by the geometric surfaces tehmselves. That means that the cube is firing the shadow rays onto the ground plane beneath it. Because shadow rays must be fired from geometry and not from points, it will always take a lot more of them than it does primary light rays.

    Here's where Blend Transparency becomes an issue. When the "edge" of a geometry is defined by an image as it is with Blend Transparency, it takes a LOT more shadow rays to carve out that complex shape than the number that would be fired if the "edge" had been made from true geometry. This issue becomes even more complicated when Blend Transparent surfaces cast shadows onto one another...layered blend transparencies....oh my!

    And that is in a nutshell the point of the MgScp files. If you want to have advanced lighting methods and a good deal of geometric complexity at the same time, you must go the extra step to ensure that the leaf shapes no matter how complicated and detailed are defined by full geometry, and to never go the path of Blend Transparency (Alpha Mapping) effects.

    When Bryce 7 was in development there was a request I made for them to give Bryce the ability to import custom leaf mesh geometries into the Tree Lab in obj/.3ds formats. People couldn't see the point of adding that functionality when  they could just use an alpha map and get the leaf shape they wanted. But I agrued that relying on Blend Trans effects will leave users as slaves to only the most simplistic lighting methods if they wanted to keep reasonable render times.

    And so here we find ourselves today. This is why I've had to learn to model plants for myself, just to avoid relying on Blend Transparency.

    Thanks for taking the time to read all of this.

  • HoroHoro Posts: 10,140

    Rashad - thanks for your elaborate comment. "Ambience is evil" probably won't appear on your Bryce tombstone but will certainly be remembered. I do have to give it to you that you got people started thinking about it.

    Ambience was one means to light up parts in shadow up to Bryce 5 and get the render finished within some reasonable time with the processor capabilities of that time. Another one was setting sun shadows lower than 100 and use the skydome, the non-shadow-casting radial at the zenith. To light up parts in shadows, Bryce 7 has better means and we have faster computers.

    Ambience is essential for glowing objects like a fire, though a light is still needed for the glow to spread to other objects. If reality is not the aim, it can be used to colour an object differently at the lit and unlit side - that can be an interesting effect.

    I'm currently working on a couple of tree related PDFs and one of them focuses on foliage made from 2D-faces. What I discovered is that Blend Transparency disables some optics related parameters. Transparent and Volume colours are not honoured anymore, whether black or white, there's no difference. Refraction is ignored as well, no difference if set to 0, 300 or anywhere in between. Though the value of Specular Halo does change the size of the glossy spot, it is ignored when rendered Premium with Blurry Transmissions. Usually, the brighter the Halo value, the more blurred the transmissions are.

    Bryce is still full of surprises. Mind that what the preview shows is not always correct. Render!

  • Rashad CarterRashad Carter Posts: 1,799

    Horo,

    Thanks! Oh yes, I am following your studies on leaves very closely!! On the issue of the halo I would not expect the specular halo color to affect the blurring of the transmissions in Premium mode, only the blurring of the reflections.

    Indeed I too have found that Blend Transparency disables all of the Optical effects. It really does do nothing other than allow customized edges based on image maps.

    The only thing that I'm curious about is when you use the typical Transparency with the slider above 0, no matter how I try I cannot avoid initiating some degree of internal reflection. I find that TIR (Total Internal Reflection) kicks in the moment the Transparency slider rises above absolute 0. These internal refelctions are difficult to perceive on infinitely thin wafers of leaf meshes, but any other geometry with any degree of depth demonstrates the issue very strongly. I hope your paper can add some greater understanding for me on how to use Transparency without introducing any TIR.

  • HansmarHansmar Posts: 2,761
    edited May 2017

    Rashad: Thanks for your answer and explanations (at my earlier renders). I wil play some more with the fog. I understand your reasoning (both of them). Problem I had, of course, is the need to land down on the water and not on the land. And landing down does work above zero level. So, if the water would have been at zero level, and if you import something at zero, you can rather simply pull it up into the stratosphere and then land it down. Of course, if there are several layers of objects, you will have to land it down several times (I sometimes also need to move partly down by hand), but by having your lowest surface at zero, you can land down at every surface. However, you cannot land down beneath zero. Nevertheless, this would not solve the issue of the fog you solved by having a low water level. I did not attempt to land up from beneath. That might have worked too, so then my problem would have disappeared. 

    I understand the effect of more clouds on the way the weather looks. Very clear. And, of course, it would lead to more or less light on the scene. Reading your explanation about the output of the sun you created, I am quite sure that I must have changed it's settings by accident. Did not do it on purpose, but it was at 100 diffuse, so you are right that it was the sunlight that was actually missing.

    I now made a new one, from the same spot with your strength of sunlight (diffuse and specular) as described, with some haze and some fog and a very different sky. I think this one works nice. I modified the IBL effect quite extensively, because, whatever I did, with the IBL that was in the scene (as background), the sky would remain blue, which is not what I wanted.

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  • mermaid010mermaid010 Posts: 5,014
    edited May 2017

    Slepalex – thanks for the comment

    Rashad – thanks for the detail explanations. Now I need to break it up into pieces so I can digest the information. laugh

    Hansmar- I like this render, the clouds and sky work well together.

    After reading Horo’s reply, I played a bit more but I was not happy with the results, I tried changing the Sky Lab settings and still not happy. After reading Rashad’s explanations I will give it another try.

    In the meantime another Landscape, this time I used the Earth Glow 3D fill lights to light the scene, the render time was approx. 2 hrs. I used a sky which either Dave or Slepalex shared with me.

     

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  • Rashad CarterRashad Carter Posts: 1,799

    Hansmar

    The shots look great. The good thing her eis that the EGFPLS is doing enough work that the sunlight can be off to the side and add a bit of a "rim" lighting effect. The sun now serves to make the image pop in the areas where you want it to pop.

    Mermaid

    Looks like you're getting the hang of these light sets. Just remember to always disable the shadow casting of all ground plane materials. Looking good.

  • mermaid010mermaid010 Posts: 5,014

    Rashad- thanks I’m still trying to understand. When you say disable shadow casting on all ground planes will that include a water plane as well? You are using a slab in your files. Will this apply to a terrain too, as I did in my last render? Thanks for your help.

  • HansmarHansmar Posts: 2,761

    Rashad, Mermaid: Thanks. I'll try some new scenes with these lights later.

  • Rashad CarterRashad Carter Posts: 1,799

    Rashad- thanks I’m still trying to understand. When you say disable shadow casting on all ground planes will that include a water plane as well? You are using a slab in your files. Will this apply to a terrain too, as I did in my last render? Thanks for your help.

    For water planes and slabs you do not want to diable shadow casting because doing so would ruin the refractive proerties. But what you do want to do is to name them uniquely so you can Excluse them from the influence of the EGDLS EGFPLS light rigs. You can edit all of the 3d fills at one time so that they all exclude the water used in scenes. I havent used a water plane in many years. I always employ slabs. Great question.

  • mermaid010mermaid010 Posts: 5,014

    Thanks Rashad yes

  • mermaid010mermaid010 Posts: 5,014

    Still playing with these files, a quick question for Rashad - What is the difference between both the MgScp Sunday Picnic EGFPLS Lite and Full?

  • Rashad CarterRashad Carter Posts: 1,799
    edited June 2017

    Still playing with these files, a quick question for Rashad - What is the difference between both the MgScp Sunday Picnic EGFPLS Lite and Full?

    The Lite version has no grass instance layers. Believe it or not even though the grass is fairly low poly the sheer number of instances means that they occupy roughly 1gb of ram. Yep, a whole gb in just grass. That is one of the key factors of consideration for resource allocation when constructing scenarios such as these.

    Post edited by Rashad Carter on
  • mermaid010mermaid010 Posts: 5,014

    Thanks Rashad

     

  • Electro-ElvisElectro-Elvis Posts: 847
    edited June 2017

    This is my first attempt with EGDLS. I especially was interested how it looks with a character. I have not changed much, except increased the quality of the dome lights to mitigate shadow banding, which is still noticable. I think the next step would be to decrease the specularity. Interesting is the blue tint of his glasses. I especially like the fooliage, it looks really great. Regarding characters skin is always the main point I think. It looks quite well here. One thing I find a bit odd is the darker spot on the guys right arm. First I thought his turtle neck pokes thru, but no, it does not. Then I think it must be shadow.

    It is a very interesting light concept, where I have understood only a tiny little bit. Again thanks a lot for sharing your experiences Rashad.

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  • mermaid010mermaid010 Posts: 5,014

    Electro-Elvis - very nice render

  • HoroHoro Posts: 10,140

    Electro-Elvis - came out quite nice.

  • JamahoneyJamahoney Posts: 1,791

    Yeah, Elvis...great effects - I initially thought his hair was oily - as some kids douse themselves in it heh he cheeky (the tint in his glasses is quite nice, too).

    Jay

  • Rashad CarterRashad Carter Posts: 1,799
    edited June 2017

    ElectroElvis,

    Very good looking render. Very natural looking pose and espression. Very engaging. Your easy experience loading in Daz Studio content to EGDLS illuminated scenes is exactly what I was hoping for. The light caresses the various angles of the models very nicely. It would be difficult to discern whether this was a TA render or not. To my eye all of the surfaces look amazing. The EarthGlow dome in this case has a tan color tint based on the tan ground plane color. This has a nice warming effect on skin tones which contrasts nicely and realistically against the blue cast from the sky. The blue tint on the glasses is an unwanted artifact, though not a deal breaker. While having specular output from the Skylight and EarthGlow domes is great for many effects it isn't always the ideal. That same blue is part of what nmakes the foliage look so good but it draws attention to itself on the lenses. In such instances one should carefully edit the name of the lens mesh so that it arrives early on the exclude dropdown list, and simply exclude that mesh from the influence of the Skylight Dome. I use names that start with AA such as AALenses. This guarantees that it is listed before the billion "Copy Ofs" which relate to instances in the scene.

    Great! Very encouraging.

    Post edited by Rashad Carter on
  • Rashad CarterRashad Carter Posts: 1,799

    Several more random renders of the MgScp Sunday Picnic. Somewhat larger renders. Fun fun.

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  • mermaid010mermaid010 Posts: 5,014

    Rashad - lovely renders. I'm also havin lots of fun with these files especially the Sunday Picnic ones. Thankssmiley

  • JamahoneyJamahoney Posts: 1,791
    edited June 2017

    So complex, but beautiful works, Rashad...bet they took lots of render time.

    As you are obviously a professional, I hope you accept my, uncritical observation in that the greens are too greenery  (too sunny-leaved) - need dulled down-ing. The light  is superb!

    Gorgeous works...would love to weave, to walk through such exotic, warm shubbery - wishing I were on holiday...heh he wink

    Jay

    Post edited by Jamahoney on
  • Rashad CarterRashad Carter Posts: 1,799
    Jamahoney said:

    So complex, but beautiful works, Rashad...bet they took lots of render time.

    As you are obviously a professional, I hope you accept my, uncritical observation in that the greens are too greenery  (too sunny-leaved) - need dulled down-ing. The light  is superb!

    Gorgeous works...would love to weave, to walk through such exotic, warm shubbery - wishing I were on holiday...heh he wink

    Jay

    Firstly, thanks so much! The renders are actually reasonable by my estimates, roughly 10 hours each depending on the amount of real estate occupied by the fast rendering sky. The nature of the greens is a tricky one for me. Without translucency nothing is going to look quite right. Interestingly, the images are more saturated out of Bryce, they lose a good bit of color when compressed to jpg. Secondly, your Oculus renders are fantastic! They almost look like real photos. Excelent use of the rounded cubes and other Additional Primitives. Hope to see more soon.

    Mermaid- Thanks!!!!! If time allows I want to produce a few more of these MgScp files to share. Have you played around with any of the interior scenes?

  • JamahoneyJamahoney Posts: 1,791

    Oh they really are gorgeous, Rashad - with a balmy atmosphere to them (again, they make me want to go on holiday to some sunny clime cool). Foliage landscapes can be very tricky as you know, but you defintely succeeded as a master in control of them.

    Jay

  • mermaid010mermaid010 Posts: 5,014
     

    Mermaid- Thanks!!!!! If time allows I want to produce a few more of these MgScp files to share. Have you played around with any of the interior scenes?

    Rashad - I tried the interior files, but I did not come up with anything worth sharing. No problems I’m still have fun with the Sunday Picnic. Posted a few more renders to my Pinterest account comparing views from the full and lite files. smiley Looking forward to more of your MgScp files, I pray you find the time to do more.

  • Thank you all for your kind comments.

  • HansmarHansmar Posts: 2,761

    Electro-Elvis and Rashad: wonderful renders; good use of the system Rashad created.

  • Has no one ever tried the interior lighting studies? No questions or comments about any of that stuff?

  • mermaid010mermaid010 Posts: 5,014

    Has no one ever tried the interior lighting studies? No questions or comments about any of that stuff?

    Thanks for reminding me about it. I downloaded some freebies but never got around working on the scene.

  • Rashad CarterRashad Carter Posts: 1,799
    edited October 2017

    I look forward to examining these studies so I'm glad to remind you. Many of the things I propose are in many ways different than what most people are used to, but it is because I often put BGryce into situations other users may not have attempted. A good example is the classroom scene from the Advanced Interior Lighting studies of this thread.

    The reason I push so much for fake GI methods is because as great as TA is there are certain scenes it cannot handle. 

    As a fun challenge for experienced TA users, please take the Classroom scene and render it with True Ambience. Any kind of true ambience configuration you'd like, and please report the tresults. This means to completely disable and remove from the scene all of the faked GI elements, and to see how TA alone would handle this particular study. It is my prediction that TA, under no circumstances, even with boost light and all the other tools, can feasibly light this scene. Considering the fact that the light needs to come from the windows, there's not much room to cheat the incoming light. Anyhow, that's all I will say until some people have a chance to report back.

    But yes, Faked GI is a necessary study in my opinion for any true sense of freedom and flexibility. Fun fun.

    Post edited by Rashad Carter on
  • HansmarHansmar Posts: 2,761

    Rashad: I now use your EGDLS set-up for my outdoors scenes. Still have not worked with your indoor lights. First things first: playing with trees is now what I do in Bryce. But, hope to come back to your indoors lights sometime too.

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