Max depth of materials is to high

[Micha]

Hi,

the guys from the VfR team told me, that at Vray for 3dsmax the max depth of materials is set to 5 per default and so it's the same at VfR.

http://help.chaosgroup.com/vray/help...aymaterial.htm

I think it would be better to set it at -1, that means the global value is used. Example: I have a train interior with a lot of materials, glossy walls, satin metals, ... and keep the max depth low helps a lot to get short render times. I want to render the scene with max depth 1 except some materials. But if I disable the global max depth 1 than I get max depth 5 from the default material settings. I thought the logic is, if I disable the global max depth, than it stay active, but can be overridden from materials that are not -1. But now it looks like I need to edit all materials and set it to -1, except my two materials with depth 2.

Please help me. Is there a trick I have overseen or can be the default material value -1?

Ciao,
Micha

[vlado]

In 3ds Max, the global value in fact overrides the setting in all materials; there is no way to do what you want there either. But, there are a number of MaxScript tools that allow to set the values for many materials at the same time. Further on, in 3ds Max it is not possible to set the depth of individual materials to -1. So in that sense, V-Ray for Rhino as actually better off

We could add an option whether to use the global or the local depth, and it could be set to the global depth by default, which would be similar to what you need, is that correct?

Best regards,
Vlado

[Micha]

Yes, an option like this could be great. So, the VfR team don't need to afraid to go own ways.

An other max depth problem I have, maybe you see a chance for Vray 3 to implement it. Could a global option a new max depth handling enable, where the first met objects can extend the max depth of further met objects? For example I have a train interior and max depth 1 works great, render times are fine. The client like to get a light frozen glass partition wall in the middle of the room and for this wall I need a higher max depth, for example 3, this can be set per material max depth. But the rays go through the frozen glass and if a chrome material (max depth 1) behind is found, than the calculation stops, no reflections are rendered, because the chrome material "thinks" there was enough depths before. Could the max depth 1 of the chrome material not allow to get the max depth 1 reflection rendered behind the glass too? At the moment all reflective materials behind the frozen glass needs a higher max depth than 1 and this cause much longer render times. What do you think? (I hope I found the right words to explain it.)

[Svetlozar Draganov]

Vray Material Control Script is extremely effective for such tweaks - you can change whatever property you would like for the selected materials or for the whole materials in the scene.
http://www.scriptspot.com/3ds-max/sc...terial-control

According to your second questions about max-depth-extend , would it be possible to prepare a simple scene for us to illustrate what exactly do you mean.
The explanation is a little bit confusing for me and a sample scene would be very helpful.

[Micha]

Here a typical example for the problem: metal set to max depth 1 and glass set to max depth 2 (only single flat surface). Same problem for mirrors - you could render a whole interior with max depth 1 without problems, but a mirror in the scene and you have a problem with all metals in the room, that are visible in the mirror.

[Svetlozar Draganov]

This is actually already possible with the help of OverrideMtl - you have to just plug the same material (as copy not as instance) into Reflection/Refraction slots into VrayOverrideMtl and increase MaxDepth values only for the Override-materials. By doing this Vray will use Max-Depth=1 from its Base material when the objects is reached by a camera ray and it will use Max-Depth=2(or more) if object is reached by reflection/refraction ray.

SceneFile==>max-depth.zip

[Micha]

Good to know that there is a way to get it done. Practical I use Vray for Rhino and is the trick there available too?

General it would be great to get an easy solution where the glass/mirror material would be edit only. Couldn't be add an option to simple extend the functionality of materials?

Or a general Vray option to switch the tracing to the new logic, that non-camera rays will use a max depth based on the previous matched material?

[trixian]

I'm not convinced this is any better than just using 3 for your main material. Does this really render faster than just using enough depth on your main mat?
There are probably really special cases where this might be beneficial for one or two materials in scenes with tons of reflections/refractions, but as a general concept? I'd hate to have to handle all these override materials.
Does anyone have a speed comparison?

[Micha]

I render large train interiors where the walls are light glossy, blurry metals are used at different places, satin glossy plastic at the seats and some times I have frozen glass walls. If I remember me right I got a 50%...100% speed improvement after I switched to max depth 1.

[mcnamex]

I render large train interiors where the walls are light glossy, blurry metals are used at different places, satin glossy plastic at the seats and some times I have frozen glass walls. If I remember me right I got a 50%...100% speed improvement after I switched to max depth 1.

you'll find some issue seeing reflective material (metal) if it is behind the glass.

[Micha]

you'll find some issue seeing reflective material (metal) if it is behind the glass.

I use glass without refraction, where I use a darker faked glass for the edges, so it looks quite good and I can stick at max depth 1. Only frozen glass needs more depth, there refraction must be used.

[mcnamex]

I use glass without refraction, where I use a darker faked glass for the edges, so it looks quite good and I can stick at max depth 1. Only frozen glass needs more depth, there refraction must be used.

ah i c, great workaround. good to know other method.