About Thea and Transmutr


Transmutr is a great tool, but when it comes to it’s in house Thea settings, I find it hard to use.

Actually, for some reasons, reflectance is always set to 100%, no matter what where the initial settings of the file, resulting in over reflective objects. Could this be fixed ?

Also, Transmutr forces the conversion of a material into a Thea Mat at export, even if the user as not made any changes (in transmutr) on said materials. Could it be possible to have the option of a simple export, that does not include any automatic Thea settings, letting the user choose afterwards if he want to adjust or not materials ?

I’ve done a test with the classic “lumberyard” scene (the parisian street), and ended up with a huge and complex scene in sketchup, that was really heavy to render as there was many maps for every materials. I just wanted to import the geometry and the basic diffuse map, but so far, this option does not exist…

  1. Do you mean that Transmutr reads the source files with 100% reflection?
  2. Or that when the reflection is less that 100% in Transmutr, it is exported as 100% in Thea?

This should be doable. Should this be a per-file setting, or a global option?

Hi thomas,

Thanks for your feedback.

  • Reflection : I have no idea what transmutr reads from the source file, but the result is always (at least on my tests) a 100% of reflection (the white slot in “reflectance”).

  • Materials: Actually it could be just a small switch : “convert materials”. If enabled, then it acts like it does today, if not, then just the diffuse is exported, with no material settings (ending up with a simple regular sketchup file )

But what do you see in Transmutr? Is the Reflection set to 100% as well?
I’m trying to determine if it’s an issue when reading the source file, or when exporting the Thea material.

Do you expect to need to set this switch every time you convert a new file? Or should this option be persistent across different Transmutr sessions?

Hi Thomas, Sorry for the late answer, I didn’t saw your previous post.

So, to be sure of the issue, I did a test from the beginning :

  • I took a simple model of a chair, clean it up and check that there were no material settings at all. I made it simple, only three materials, and only two textures.
  • I exported it from sketchup in FBX and ended up with a .fbx and the two texture in a folder.
  • I imported it in transmutr and “transmuted” it right away, saving it on my desktop.
  • I opened the resulting .skp, and, at first, things seems to be ok (in sketchup viewport), as I had exactly the same chair as in the original file.
  • I launched Thea and took a look at the materials, and I encouter two issues :
    – The diffuse bitmap was missing (I think it is trying to get the one that is in the original FBX folder instead of using directly the one in the sketchup scene).
    – The reflectance slot was at 100%, even if materials have never been set previously, in any engines.

Here it how it looks in Transmutr (materials have, for some reasons, some default parameters):

And in sketchup :

In Thea

Here is the initial model, if you want to test it directly.


So, actually , what I think it should do, is, first, look for the bitmap in sketchup, instead of the one in the folder, just as Thea do most of the time.

Then, I think there should be some switch at the top of the “materials” tab, stating something like “convert materials : on / off”. This switch could remain on the same position between session, remembering users preferences, and be maybe the default option.

In this case, a material in thea4su should look like this :

Instead of that

What did you use to export to FBX?
Could you send me the FBX instead? With texture files as well


Here is the file, it’s just an export with the built in sketchup exporter. The result is the same than with imported FBX from unknown source found on free3d.com for example.

VITRA JILL.zip (1.4 MB)

And, I just did a quick test with an .OBJ and the result is exactly the same, so it’s not an FBX thing…

Thanks for the file.

Ok so I see what’s going on.
Transmutr’s “Reflection” setting is actually mapped to Thea’s “Roughness” setting, not “Reflectance”. Sorry I forgot about that.

I think I remember reading somewhere (on the Thea forums or a tutorial) that this is the physically correct way to handle reflections.

Regarding Thea’s Presets, it would be too complicated for us to handle all of these cases separately, that’s why we use the “Editor” materials that can handle everything we need.

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Hi Thomas,

I’m coming back with this Transmutr and Thea subject. I had to do several file import recently, and Transmutr handling of Thea’s settings is still not good. Could it be modified in future updates ?

So, when I talk about "Thea’s presets’, I’m talking about the initial panel of the app, where material have no informations, they’re just a basic sketchup diffuse, if the user do nothing. I think materials should be in that position if nothing has been adjust in Transmutr.

About Reflection/ Reflectance in Thea, it’s corresponding to “Reflection color” in Vray, and “Roughness” is corresponding to “Reflection glossiness” in Vray (but with an exact opposite setting : 0% Thea roughness = 1 Vray glossiness).

Again, it’s a really important subject, so I hope it will be taken into account. A simple “export with no Thea settings at all” will be good enough as a start.

Thanks in advance.

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Please, Thomas, don’t forget to add the option to link Thea materials using .mat.thea files. This option is also very useful in these cases

In the future we plan to have an “advanced” mode that will expose more material settings, like reflection glossiness/roughness. But for now Transmutr only offers a single Reflection setting.
For V-Ray, that setting actually controls both Reflection and Reflection Glossiness at the same time.
For instance, if you set the Reflection in Transmutr to 0.6, you will get a V-Ray material with 0.6 Reflection and 0.6 Reflection Glossiness.

Do you think we should do the same for Thea?

I wish, but as you can read in that thread, I don’t have enough information to implement it.

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I don’t think that linking Reflection and Reflection glossiness is relevant.

One is the amount of reflection, the other is the quality of this reflection, and they’re totally independant.

To me, and sorry if I’m repeating myself, the most important thing to have now, considering that Transmutr don’t handle well Thea settings, is to have a simple “no Thea settings at all” button. Just an export of the diffuse material in native sketchup format, with no other information.

Is it doable ?

The thing is Transmutr is not meant to be a full-blown material editor. We support three different rendering engine, and we have to choose what settings to expose, and make sure not to clutter the UI.

I added buttons to disable exporting materials for specific rendering engines. This will be available in the next release.



Sure, I fully understand that it’s hard to support in the same time different render engines.

The addition of the “disable button” is enough for me, thanks a lot !

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