Scale-independent mapping

[Art48]

Hi,

Is there a possibility to use for example the VRayTriplanarTex in a "scale-independent" mode?

Reason for this is the following:
The scale in which we get CAD data from clients varies much. Often it is in mm, sometimes cm, sometimes inches etc.
In order to preserve for example STEP Data accuracy I merely scale the objects, but not ResetXForm them, since I'd have to collapse the stack, losing the quality of the STEP file / Body Object.

This results in me having to check the materials from our library every time, if the tiling is okay, etc. Of course I could make three different versions of the same material, for each import system unit one material, but I do not think that is practicable.

How are you guys dealing with this issue? For me personally a bitmap node, or, like I said, checkbox for the VRayTriplanarTex to ignore scale and thus acting similarish to the "world XYZ" mapping mode from a scale point of view, but like a "local XYZ" mode preserving the rotation and position on the object.

[joconnell]

I've found it very to use the triplanar with "reference to another node" space. I'm working on a gigantic scene and the scale spinner won't go down far enough without me increasing max's decimal spinners a lot so it was really handy to just have a point helper that I could randomly scale up and down and control my mapping.

[Art48]

Meh, that step makes some sense in your case, but in general doesn't really help me, since it is also a step required to do as is the adjustment of the shader I have to do currenty. Additionally I'd have to pay attention that the reference object is aligned (rotation-wise) with the actual shaded object, which means I'd have one reference object for each uniquely rotated actual object in the scene, which is also not practicable.

All the scale stuff is so deep in 3ds max that I fear the only solution (until one exists from Chaosgroup) may be to have a custom VRay Property per object, with some kind of factor, which could be generated automtically, and then in the shaders itself look for that factor and use it... In general this may be a solution which would work but it would be a lot of work to initially set up and also require all the shaders to be set up this way. I'm still hoping there has to be some better solution.

[joconnell]

Hmm - I wonder could you try something like using the uvw xform modifier? Say you're scaling things to do unit conversion, there's a factor of 2.54 between inches and cm, that's a number that could be detected by reading the scale of your object with maxscript - you could then have it add on a uvw xform modifier with the appropriate scale to bring your material back into line?

If you've got specific conversions you use every single time then there's a pattern that could be found easily and processed for this specific use case.

[Art48]

Hm...I'd have to test the UVW XForm way, but doesn't VRay's TriplanarTex do its own mapping? Then the UVW XForm way would only work with regular UVW mapping.

[joconnell]

Yeah, triplanar does alright, apologies for not fully reading your original post before jumping in! How many objects do you think you'd have in your average scene? I'm wondering if there's another way to achieve this using the existing tools - will adding an xform modifier to the step object result in a mesh being output, even if the stack isn't collapsed?

[Art48]

Yes the modifier results in mesh output.
The object count can vary wildly from a few 10s to several 100s and in rare cases 1000s.
My dream would be a solution which works for all object numbers with as few manual steps as neccassary.