I have bought VRay for some reasons but I also work on older projects with Mental Ray. In version 2017 all was fine. In version 2018 the presets for lawn etc. will not render. Trees and other plants are rendered. But some of them only in black (HQ-Plants). There are different warning messages from the renderer, which doesn´t came up when I render the same scene in 2017. For example:
MSG 0.0 71 MB error: The transformation matrix for object "_forest_template_One Plane|Instance(Mesh00)" contains a zero scale in (x/y/z), which is invalid. The object will not be rendered.
MSG 0.0 71 MB warn : expected structure "E" missing from "m" shader declaration
MSG 0.0 92 MB error: Texture map "Map #10 ( Forest Color )" is not supported by Mental Ray and will not render.
I have NVIDIA licenses of MR to work with Max2018. But it seems, that MR has a very different code than the previous version. The installed Version "NVIDIA Mental Ray for 3dsMAX 2018" shows a version 1.0.1. But when I register in the NVIDIA Professional Application Center it says, that it should be MR version 3.14 f or 3dsMAX2018. When I downloaded it from the NVIDIA Advanced Rendering it also says, that it is version 1.0.1. I´m confused. Is there any workaround or which version of Mental Ray I should use? Lucky me has also VRay and I will do my new projects with it. But sometimes it would be fine to be able to work with MR too. Any suggestions?