Tue Jun 6, 2017, 12:10 PM
I have been interviewed for Digital Art Live magazine, you can read the full article here, Digital Art Live Issue #19
or download the PDF version here, Digital Art Live Issue #19 PDF
The methodology behind building complex scenes in Iray will be explained in detail in the next journal. Thank you all!
Special thanks to Aarki
Fri Mar 4, 2016, 4:00 PM
About a year ago I decided to create a CGI science fiction comic from scratch. After searching for solutions on the internet I stumbled upon the Daz Studio website and recognized the style of images from CGI I saw before on Deviantart. Victoria 4 and earlier body meshes don't look bad but all renders looked too similar and I always had the feeling that they needed a lot of improvement to be able to use them for something I want. Nvidia also released the Iray render engine about a year ago and decided to cooperate with Daz studio. Interesting fact since the resource pool for daz studio content is huge on different websites, the import options for external resources are even bigger and iray has lots of great features to make rendering more realistic. A choice I have not regret ever since.
Only one chance to make a first impression, so better take the time and do this the best possible way. A comic gets only as good as the story gets and storytelling is an art by itself. Most CGI comics I see on Deviantart are focused on the story or the visual part but lack the combination of both, something that I believe is due to the fact that most people don't want to put too much time and effort into something that looks impossible to do by themselves. I like a big challenge like this because 3D is something you can master when your skills improve and your knowledge grows, it's just a matter of time. I can enjoy creating a single prop to use in the bigger thing but I find more joy in creating the bigger thing and let others perfectioning the things I want to use, after all they have already put so much time in creating that I couldn't possibly do it any better. Using someone else's creation in a massive piece like this comic is maybe something that the creator will appreciate, it usually means they have made something versatile enough that reached the highest quality level. Creating a rich universe with characters that tickle your imagination enhances the immersion, a lot of thought has been put in every detailed character to make them believable with their own background, what they want, what their secrets are and how they look. Character profiles are coming up next to reveal parts of the story or to provide background info to make the reader more interested in understanding why these people are who they are.
I get the question sometimes when I will start with the comic or why it takes so long before there is something to see but I don't want to make the same mistake twice like I did with my prologue chapter, even when it was intentional to have it as an experimental chapter. Extensive testing of all props and figures sometimes reveals things that are unforeseen and changing a character in the middle of a story is not done, it has to be perfect from the start. It is however only logical that characters enhance but not at their very basics. I converted some G2 characters to their G3 version while I kept others at the G2 mesh base, the question is not if one is better than the other but it creates more diversity among characters and the resource pool is bigger that way. Autofit clones are perfectly fine but can become your nighmare when you have to finetune poses. The biggest difference is the fact that iray was fully integrated when G3 was released so skin shadering has improved a lot since G2, most G2 figures I use are using my own experimental skin shaders but look realistic enough to use. Another holy grail to be found is good looking hair, an issue that will always be there when rendering, using enhanced subdivision geometry and adapted hair shaders solve a lot of the visual part but it's trial and error most of the time. True realism is still far off but we have already a lot of tools in our hands to make the best out of it.
Enhancing subdivision geometry and using 4K textures are my best friends but are a big job to compute so hardware requirements are something to take into account, I had to double my amount of system RAM to 32Gb to be able to work within Daz Studio and its iray preview pane. The Geforce GTX970 with 4Gb vRAM is a good subtopper, even for render tasks so that will do for a while. Compiling shaders and trying to preview a render at high subdivision levels sometimes takes up to 32Gb of system ram, not having that would make one go insane and make Daz a very unresponsive application. Using a lot of different highres textures also makes your Vram fill up fast and will make your Windows OS unresponsive if you want to do something else during rendering.
[Iray tips] Iray render quality settings
Render quality settings are not always very clear because the outcome is heavily influenced by what it is you are rendering. You have the choice between render quality, render end time and maximum samples value. Thruth is, they are all connected to each other and it is always one of those three that defines your 'end' setting. Rendering props and characters at base resolution or high resolution SubD 1 is mostly ended by the render quality setting. Standard value is 1 and in most cases the render will finish in well-lit environments without grain at that setting. The darker the environment the more chance you will have to see grain in the darkest parts or where lots of high-gloss surfaces influence each other and you will have to increase your max samples value in that case. When using higher SubD values for body mesh, hair and clothing you will notice that render quality 1 will be insufficient for grainless rendering so it's better to adapt your quality setting to something higher during a render to avoid this in a finished render. If you see the number of iterations progress very slowly you might want to leave render quality at value 1 and set the end time to its maximum and visually judge the quality for the presence of grain, your max samples (iterations) value is standard at 5000 and it's possible you might never get to that value under these heavy circumstances. It's safe to say that after 2000 iterations you might be able to see if a render will be succesful or not, depending on SubD levels the equivalent of 4 hours. Don't take this as a reference, it's just a personal experience.
Thanks for reading!
- Listening to: Snow ghosts ft. Blue daisy - Covenant
Sat Aug 29, 2015, 10:11 AM
5 months ago I needed a tool for creating a CGI science fiction comic I had in mind and after searching the internet for appropriate applications and solutions I came across the daz3d website. I knew these kind of images from deviantart but they never were immersive enough to get my jaw dropping. Buying stuff was easy since for me it was like working towards a concept rather than buying stuff and do something interesting enough with it to publish. I know now there a lot of good artists out there who are able to do some magic with the older genesis figures, props and physical based render engines but the end result always looked stylized. I started with a few props, a victoria 6 model and rendering with 3Delight, a very good render engine if you know how to work with it. It didn't take long before running into some limits where colourful dots started to appear in my renders, after looking up this was caused by the total amount of light being over 100%. Working around flaws already after two weeks? That couldn't be true and then Livius70 commented on an early picture and told me to take images like this to the next level with the newly released iRay engine. Easy choice because I wasn't already entirely emerged into 3Delight, the new engine was made by nVidia and would be using your video card and cpu to render. One month earlier I upgraded my entire system to the next generation with a fast quadcore, 16gb fast ram and a GTX970 with 4gb of ram. Exactly the kind of combination Nvidia said that would benefit from using this new render engine. So a new render engine and a new workflow, easy for me to go all custom made and get to learn daz studio and iRay a lot better. Starting my comic and learning at the same time could be done through a test chapter now being published as the prologue. You can see progress and changes throughout this chapter while still preserving the consistency of the story so more please!
[HDRi-SS Sun node]
Everyone renders differently in terms of style and used techniques and I slowly developed my own distinctive style. In my search for immersion with iRay it became clear that there are a few things that really add flavor to a scene. I like to build large scenes that can be used from many angles for lots of purposes, in my case an outpost or part of a city for a comic. I believe HDRi maps are great for studio lighting and blurred far distance when building large scenes but still seems a bit off compared to the rest. Maybe it's my fixed idea of thinking but a complete scene built from textures and shadered objects looks too different from the HDRi map picture. iRay provides another way of lighting a scene and comes in the form of what they call a 'Sun node'. Simulating the sun is great to use in outdoor scenes and provides great looking images without much effort. It took me a few weeks to be able to use this how I wanted because the time of day setting that is available is not very handy to use so by accident I discovered when setting the SS Sun node to a dedicated camera the camera position defines the direction of the way the sun shines so you can have the shadows being cast exactly where you want them. While experimenting with this I noticed that lowering the camera and put it in a more horizontal position also defines the time of day so it's pretty easy to simulate dusk or dawn with this with the appropriate amount of light. I tried some closeup portraits when using a ss sun node only and the results are not bad but also far from good. Skin shaders look as if they are missing some essential parts of the light spectrum so adding some emissive lights could help here. SickleYield had some good advice on how to add emissive lights without showing them rendered, great info to remove the hassle of finding a way where all emissive lighting seems to be coming together in the reflection of the eyes.
Stephja brought this to my attention because I was experiencing some strange artifacts in the form of black spots. His first idea were the little black triangles popping up on body meshes where the mesh polygons were stretched. The default subdivision level value is 1 with Render SubD level minimum is also 1, increasing this last value further divides the surface and minimizes this issue and finally solves it, however at (dramatically) increased render times. I started experimenting with this and increased the minimum value to 3, the results for lighting and shadows for the body mesh are awesome but adding clothes shows another issue. Most clothes don't have the ability to change the SubD levels by default but you can always convert the object to SubD in the menu (Edit-Object-Geometry-Convert to SubD). When you preload the scene in iray there seem to be no issues with pokethrough until the moment you start doing the actual render. You have to increase the size of the clothes, use the good old cutout opacity levels of the body mesh or find some other way to work around this issue. So it's searching a bit for the correct settings to use this but the visual result is stunning, however I have the feeling that setting the minimum value to 3 also triples the render time.
The best ingredient to make a scene breathe and provide immersion is the correct implementation of volumetric effects, easy to overdo and hard to master. When iRay was released it was just a matter of a few weeks before someone found out how to do this in a very easy way with daz3D and it was again SickleYield who pointed out this in one of her journals. The way to do this couldn't be easier but also affects render times a lot and depends on how you use it. One of the most important things when using this kind of technique is to make sure you let your render finish to the end, having it manually stop at 80% provides you with an unfinished image where the fog looks like grain and the background behind it is way too blurry.