In addition to the new LPE buffers we presented earlier, iray now also has another neat user buffer: The Irradiance Buffer. Independent of the primary hit materials (i.e. textures, procedurals, layering, BRDFs, etc. that are used to describe a material), it contains the amount of (simulated) incoming light for all the points visible from the camera (which is not the most correct formulation for...
Procedural Sun & Sky (and setting it up)
A change that slipped through mostly unmentioned is the procedural Sun & Sky. Previously, iray had to bake environment shaders upfront to support all kinds of custom shaders in the most compatible way to avoid manual replacements of shaders. Nowadays we try to support as much as possible natively in the core. As a result, Sun & Sky can nowadays be changed interactively, but of course...
As it has been a while since the last update (shame on us, but we have been busy implementing useful features :)), here a (technically) less spectacular, but rather popular and useful new feature: Of course, multiple section planes can also be combined: In addition, the section planes can either work as if they cut off the geometry completely (so let the light in as in the pictures...
Instant Relighting & Nonphysical Effects
Today, we would like to give you a glimpse of one of the new features of our renderer. Often, the image generated by the renderer contains all the effects you want, and looks roughly right. But you still may want to emphasize some areas, increase a highlight here, dim a caustic there, maybe tweak the color of a light source. You could modify your scene and re-render, but re-rendering frequently...
This bit of eye candy shows the magic of a thin beam of light being refracted through a (diamond!) prism. —— daniel l
iray Next & Dispersive Caustics
Today, we have another great example for the improvements which are coming to the next major release of iray. Here’s our test scene rendered with “iray classic” (what you would expect from iray 2.x): And here’s the scene rendered with “iray next”: This scene makes heavy use of subsurface scattering, caustics, and dispersion (those two gargoyles are made...
iray Next: Sneak Peek
We’ve been working on improving iray to make it better at rendering difficult lighting conditions. The results are good so far, so we thought: how about a preview? Let’s first look at the scene used in our post on frosted glass (http://blog.irayrender.com/post/19731699592/frosted-glass-part-ii). Before & after: Those “shadows” are actually indirect transmissive glossy...
Shadow Acne and the Shadow Terminator
Looking at the title of this post you may wonder if the iray guys now completely lost their minds. But actually this is more or less scientific terminology for effects that each artist has (unfortunately) experienced at least once in his/her lifetime. iray (fortunately) solves one of them, but actually fails to solve the other, as do all other physically based rendering packages out there. So this...
We received some questions in the past on (the lack of) texture filtering options in iray. With this post i want to shed some light on this and why we decided to not bother our users with such low level implementation details. iray by definition doesn’t require to use common texture anti-aliasing techniques like MIP/SAT-mapping and trilinear filtering, or even view dependent techniques like...
iray Material for 3ds Max
This blog has seen several posts on the capabilities of the iray material model. So far we’ve shown: Metallic flakes Sub-surface scattering Thin film coating And there’s a lot more that we haven’t shown. Today, life gets a little more wonderful for all 3ds Max users: we’re finally introducing the iray Material plugin for 3ds Max (2013). The plugin is designed to be...
Thin Film & Soap Bubbles
Here’s an image I rendered for EUE 2012, showing off iray’s thin film coating feature. The bubbles are made of simple spheres (deformed manually). The material is basically water, but with the “thin film coating” feature enabled. The bubbles reflect an HDR environment map (and each other!). I placed a dark green object behind the bubbles, somewhat mimicking foliage, to...
Matte Object Example
Here’s an animation created using iray matte objects: The scene was created by combining this backplate photo: with three water-filled glasses and two miniature cars. A chrome-ball image was used for environment lighting. This example demonstrates the panoply of interactions, between synthetic and matte objects, which iray is able to simulate: reflections refraction direct and...
iray and product rendering
In this blog entry I am going to write about adjusting materials in iray. Since I work a lot with audio hardware in my spare time I recently decided to model an audio mixer that would be too large for my home studio. But being a 3d model, it doesn’t consume any physical space and I can take virtual pictures and send them around as if it were my own. Modeling I wanted the audio mixer to...
End User Event 2012
I’ll be at EUE in Utrecht in two weeks, to provide some tips, insight on the iray roadmap, and show off iray’s latest production features. Don’t miss it… http://www.enduserevent.com/ —— daniel l
iray Matte Objects in 3ds Max 2013
Our last post introduced the matte objects feature… Today, we’re showing you how to enable and use it in 3ds Max 2013. Disclaimer The feature we’re about to demonstrate isn’t official in any way. It’s neither exposed nor documented in 3ds Max 2013. It received very little testing and end-user validation: it’s still in beta stage. While we invite anyone interested to try it out, it should be...
Matte Objects in iray
Today we’re introducing the latest iray feature to be released: matte objects. Overview Let’s start with quickly going over what matte objects are all about. Say you have a photograph (which we’ll call the backplate): … and you want to add some synthetic (computer-generated) objects to it. In our case, we want to add some lumber that’s been left behind on the pier. The obvious starting point...
iray on Kepler
Kepler, the new generation of NVIDIA GPUs, is now shipping within the new GeForce GTX 680 card… But an important note to avoid surprises: iray doesn’t run on Kepler GPUs (yet!). The binary code for this new GPU generation is different from the previous one, so you will need a re-compiled version of iray for Kepler-based chips. Rest assured that we’re working with your favorite...
Frosted Glass, Part II
In today’s installment, we take a closer look at the shadows cast by frosted glass objects (or any glossy transparent material). The image above re-uses the setup from our previous post: a Sun & Sky, a cylindrical light source to produce highlights, and a few high-tech teapots. We see five glass panes which get progressively more frosted: from specular (glossiness 1.0) to very frosted...
"Zippering" and Banding quick update
As some people seem to have serious zippering or banding issues currently that are hard to come by without changing the look of the specific scene, as a quick workaround, try to use the following clever “trick” by Jeff Patton: Adding a noise map to one of the slots of an affected material can succesfully randomize the patterns/banding, i.e. you replace it by a bit of noise. Thanks a...
Frosted Glass, Part I
Frosted glass is a hot topic as many users seem to struggle with rendering it realistically. Today’s blog post looks at different ways to create frosted glass. The following picture shows four frosted glass panes rendered using three different methods. The scene is lit with a Sun & Sky system and a cylindrical light (the white horizontal bar) is used to emphasize reflective highlights. Before...
Sampling artifacts aka "Zippering"
As some may know, especially given the history of the mental ray production renderer, iray makes heavy use of QMC sampling to produce its photoreal renderings. Unfortunately this lead to some artifact problems lately, infamously known as “zippering”. So what does QMC sampling actually mean? I’ll simply use two illustrative examples that actually my former boss came up with in...
Refraction and IOR stacks
Ever wondered what the correct way of modeling water glasses (and other refractive materials) in iray is? This blog entry will shed some light on it. iray uses a rather smart way to detect how these kinds of objects are actually modeled and tries to make the best out of the given representation automagically. This means that one cannot break the engine when modeling hierarchical refractive...
Let it SSSnow!
Back in November, we published our first blog post on metallic flakes. Flakes are really cool, but we only scratched the surface of what our new material model can do. Today, we’re scratching a little more. Has anyone taken a close look at our blog’s banner? It’s nothing fantastic, but for developer art it’s really something (it’s not a teapot!). We created it with some special materials to see...
Physically Plausible Scene Setup
While iray itself is capable to produce photorealistic pictures, one issue we are seeing in quite a lot of scenes that we get from customers, are weird material, light and tone mapper settings. So as a result, you can have a strange looking shot of an otherwise nicely prepared scene by using a non-natural light and material setup, or choosing the wrong camera parameters (aka tone mapper). To...
There is one main issue that renderers based on fully featured, physically correct ray or path tracing are facing: Rendering can take a long time to become completely free of noise. Unfortunately this is due to the nature of (quasi-)Monte Carlo based algorithms in general: The mathematical error of the estimate does not vanish linearly. This means for iray that the amount of noise is not directly...
Daylight Portals in iray 2.0, Performance Issues
A classical problem with global illumination is that of lighting interior scenes with exterior light sources, typically a sun/sky setup or an HDR environment. While this type of setup creates realistic interior lighting, it’s very difficult to compute if the renderer relies on brute force (quasi) randomness to find the windows and openings through which light is expected to pass. Daylight...
Let there be some metallic flakes!
It seems like CG artists always want to render cars, the amount of actual iray user scenes we get that are cars is remarkable. It’s like a fundamental constant of the universe. So if a renderer cannot do cars it’s useless for a German. Luckily iray is quite good at rendering cars… but of course there is always room for improvement. For iray 2.0 we focused on the features of our...
Hello iray users! We are excited to be able to reach out directly to you with educational material, feature demonstrations, and workflow examples incorporating iray. We will discuss here useful tips and tricks and might post interesting work from the community. You may also gain some insight into the vision and philosophy behind iray. Please stay tuned… - The iray Developer Team