opacity texture applies on surface not on object

[francoisBA]

Hello,

I just noticed that a black-white gradient used as opacity, is only applied on the external surface of a tube, not on the complete object (volume).

As you can see in the red area, the inner surface of the tube is not affected.

Is there a way to bypass this issue ?

Regards

[francoisBA]

I made a rendering until the end.

We can observe it kinda works on external surface, but :

A - inner surface is not affected by opacity gradient

B - upper surface is completely visible when opacity should be 0%

[Ussnorway]

1. you are confusing opacity for translucence
2. yes Adobe Dimension is crap at rendoring translucence since they moved away from Nvidia back in build 3... if you need correct rendors of translucence then I would use Blender

[francoisBA]

Hello @Ussnorway,

Thank you for technical feedback.

I am not confusing. If you look closely the first screen capture the inner surface (circled in red) should act as the outter one (in green), as the opacity gradient is applied on the entiere object.

My objective is to get a fading object (from 100% to 0% at the top).

Then the upper surface should completely disappear.

About Blender, I started looking at it.. but their dimension's management is such a pain…

[davescm]

Resolving your issue depends on how the model is unwrapped. If the inner and the outer surfaces share the same UV location (not normally good practice but could be useful in this instance)  then a single gradient would work, if they do not then a separate gradient would be needed on each part of the UV map.

You said , "About Blender, I started looking at it.. but their dimension's management is such a pain…"

What problem are you having with it? I use Blender a lot and have never had an issue with dimensions. Just set the units to real world units and go.

Dave

[francoisBA]

Hello @davescm, thank you for your feedback.

In this specific example objects are made directly into Dimension, with the preset tools.

I work with OBJ files too, made from very large STL, I first explode in MeshMixer, clean up then reassemble creating texture groups before I export into complex OBJ file. As you seem to know more than me about OBJ, I'm pretty sure you would really enjoy my workflow. (I miss working with IGES files and Keyshot… 😄 )

Do you know if Dimension 3D objects are generated in OBJ format ?

About Blender, I noticed you can change dimensions and scales from at least two different windows in the interface, independently. If you change dimensions from window B, model is updated, but dimensions in window A aren't updated, and they are wrong.

I asked a colleague who is also very talented on Blender and didn't believed me at first. But she tried and confirmed she had no answer for this issue.

Another example is when you use a modifier (I don't know the exact term in english), you can apply a scale factor on the object, but main dimensions remain the same.

Do you think all of this can be fixed with units set to "real world" ?

[Ussnorway]

Do you know if Dimension 3D objects are generated in OBJ format ?

By @francoisBA

Dimension objects are Dn files which is almost but not exactly the same as Obj

if your workflow needs Obj then you can normally export from Dimension as Obj but then I would open that model in Blender and export it from there as wavefront | Obj so that you match the standard