Lightweight Placeholder Material

Let’s say my goal is to have really lightweight object placeholders in Sketchup but to render them in V-Ray using their full original geometry and textures, and that my source is Megascans (currently using Transmutr 1.2.4 with V-Ray 5).

From Quixel Bridge, I export a Megascans asset to Transmutr. Then, in Transmutr, in the Geometry tab, I simplify to wireframe bounding box or 99 % mesh simplification, and switch on “Export as V-Ray proxy” and keep the other renderer’s proxies switched off. In Transmutr, in the Materials tab, I switch off all Exported materials except V-Ray. I would like to control Sketchup materials as well, but clicking the Sketchup logo button here does nothing.

When I then transmute, Transmutr makes a Sketchup component whose geometry and albedo and bump seem to render fine in V-Ray.

Still, I have one issue.

Transmutrs seems to force the use of the original source fullsize albedo map as Sketchup’s material. No matter its bytesize.

This means that even though the placeholder component’s geometry weighs only perhaps 0,1 MB – which is good – I still end up with a proxy that easily weighs 15,1 MB, or 20,1 MB, or more, because one single Sketchup material inside weighs 15 MB, or 20 MB, or more, from a default 4K source.

The Sketchup material’s bytesize is excessive. My simplified crooked placeholder does not need such a heavy overcoat. Add 40-50 placeholders, and the Sketchup file has already passed the 1 GB mark just in *.skms.

But perhaps I am doing something wrong here.

After Transmuting, I tried to manually in Sketchup switch out the needlessly huge texture to another texture of trivial size. Turns out this seems to work just fine and V-Ray would go on to render correctly. If this can be done manually, it could be done automatically.

The point of Transmutr’s proxy placeholders is to not to bog down Sketchup with needless data but to use pointers instead. So I wonder

– How can I make Transmutr output placeholders with arbitrarily lightweight sketchup materials?

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This is a good idea, I will add it to our todo list.

Although I’m afraid we won’t do it in the near future, as our efforts are focused on Skatter v2.

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All right, thank you very much.

As I see it, a good solution could be if users were able to pick a proxy material quality in Transmutr. Similar to how Transmutr currently offers a choice of proxy geometry quality.

There could be a proxy material quality slider, along with an option to simply use say a 10 kB albedo-coloured UV checker. Or something similar.

While 10 MB of geometry is likely more demanding on Sketchup than 10 MB of single material, the median albedo map filesize of common texture sources is growing faster than Sketchup’s performance is. As long as this is the case, a placeholder material control feature remains motivated.

We are all looking forward to Skatter 2 and new iterations of Transmutr!

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