iray developer's blog

iray 1: iray in standalone mental ray

* As far as I know, we can only run mental images' iray in NVidia's RealityServer. I hope Autodesk 3dsmax/maya/xsi supports iray soon. mental images (a subsidiary company of NVidia) demonstrated iray renderer in GDC's keynote and SIGGRAPH ASIA 2009. GDC NVidia iray demo (YouTube) mental images iray page mental ray or some other renderers can simulate indirect illumination in some extent, but the methods final gather or photon map are quite rough approximation. They have no guarantee to converge to the correct answer. Also there are many renderer parameters for performance optimisation. These parameters heavily depends on the scene. It is difficult to achieve high quality and faster rendering. These methods are anyway time consuming, therefore, we sometimes put invisible light sources by hand, that simulates indirect lights. This iray is a brute force path tracer and there is no renderer parameter, but nowadays computer has not enough power to compute the light tran...

The architecture of mental ray

Figure 1 shows the standard mental ray architecture. Figure 1 standard mental ray architecture. F1: Application scene file: Application proper file. For example, .max (3dsmax), .ma or .mb (Maya), .scn (XSI). F2: .mi file: mental ray scene description file. If the DCC software has mental ray plugin, or integrates mental ray, they usually support .mi file export. (A2) 1. Application: DCC (Digital contents creation) software. For example, Maya, 3DSMax, XSI, CAD program, and so on. 2. mental ray core: mental ray core program. There are library version mental ray and stand alone mental ray. The library version mental ray is usually invoked by a DCC application via translator module of the application. A translator is a module of a DCC application which translate the DCC application's internal data structure to the mental ray data structure. The stand alone version mental ray reads a .mi file and performs the rendering. If you have only mental ray core, mental ray does not work. mental...

What is shader?

Shader is one of the important component of mental ray. Let me tell about it a bit. A shader is a program code fragment that computes how light interacts with objects. This was the original concept of shader in early computer graphics time and nowadays the role of shader and its meaning are expanded. In one of the common scenario in computer graphics, objects are usually represented as polygons. First, the intensity of each vertex is computed, then inside the polygon is filled by an interpolation method. This becomes more complex as the computer graphics technology developed. There were two shader development directions. One is a hardware rendering that concentrates rendering speed and interactivity. The other is a software rendering that concentrates the image quality. Nowadays graphics hardware is called GPU (Graphics Processing Unit). The early stage GPU has fixed functionalities. Because fixed functionality can be achieved more performance in practice. The implementation was based ...

taming mental ray (English version)

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