iray developer's blog

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...

iray 5: iray in standalone mental ray

So far, I told about exporting an mi file. Now here is the shader conversion for iray. iray supports mia_material. To reuse current scenes, it is nice if I could convert the 3dsmax shaders to mia_material (Arch&Design) shader. I could imagine that some of other shaders will be supported also, but, iray is a CUDA program. CUDA has a divergence problem, it means, if many kind of shaders are in the scene, the performance becomes low. That's natural. A shader is a function and many different shaders are running on a CUDA device, I could see it will be slow. But, if the same function everywhere, then CUDA works well. (in theory. If function itself has a lot of branches, then there is a problem. Though many obstacles are there, but many kind of shaders seems to have not so chance. ) Also I imagine there is less trouble if I use the mental images native supported shaders since iray is a new renderer. In my personal opinion, I would convert the shaders. You can find 3dsmax shaders ...

iray 4: iray in standalone mental ray

As an example in here, I create one teapot in 3dsmax and assign a mia_material (Arch&Design). Since 3dsmax exports an mi file with 3dsmax shader dependency, mental ray standalone could have a problem to render that mi file. mental ray standalone usually doesn't have 3dsmax shaders. The main advantage of the standalone mental ray is parallel rendering on a render farm. I couldn't tell the legal license of the 3dsmax shaders. For the safe side, if we have no dependency to the 3dsmax shaders, it shouldn't have a problem. (Or you can also install 3dsmax to all the render farm machine, though it doesn't make much sense.) If I just render the mi file from the 3dsmax without modifying, I see the following error. --- > ray -x on -v 5 00teapot_ex00.mi ... LINK 0.0 error 191007: cannot load 3dsmaxhair.dll, The specified module could not be found. ... LINK 0.0 error 191007: cannot load mayabase.dll, The specified module could not be found. ... LINK 0.0...

taming mental ray (English version)

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