Vray IPR changes

[CharlyRT]

Hi, havent use Railclone in a while, but is it a possible way to see changes while on IPR in Vray?
Im creating a simple style and its impossible to see what im doing I need to stop and start again while Im changing settings on the style

[Michal Karmazín]

Hi,

For these purposes, you can disable the Display > Render > Use Instancing Engine option - in most cases, it shouldn't lead to a big performance hit - just please be aware of using heavy geometry as the whole RC object will be treated as a single mesh. Using the Points-Cloud mode would be highly recommendable. Let me add, that as mentioned in this tightly related post: "... the IPR/IR mode has several limitations (in V-Ray and in Corona as well) and it's hard and sometimes even impossible to fix issues that occur with the Interactive Rendering as 3ds max wasn't primarily designed for it - a series of cheats are being used (from the renderer side and from our side) to make it work... "

I hope that helps.

Best regards,

[iToo]

This is a limitation with all interactive renders, including IPR:

RailClone generate and keeps on memory a complex set of data, including instances and custom meshes.
Usually data for viewport is different from render, due to the Display setttings.
But when using IPR, there are multiple render and display threads running simultaneously, requesting each one their own data. For this reason, we disable the viewport visualization.

The only solution for this, is to generate two separate data sets (one for viewport, and other for render). This is the way that Forest Pack works.
We tried same approach with RailClone, but it caused a lot of side effects, because code is more complex that Forest. Besides this technique have a significative performance hit (object must be rebuilt two times).

To make things even worse, there is not a standard defined in 3DS Max for interactive renders. Each render engine (V-Ray, Corona, etc.) use their own method, which force us to implement multiple workarounds in the code.