Tri-planar texture: random texture offset and scale in SketchUp viewport

[Antioche]

Hi,
I am trying for several hours to use the tri-planar texture random offset settings to randomise the textures on objects, but there is something that puzzles me,

When the random Randomization > texture offset is activated, the different tests I have done seem to show that the offset is calculated as a random factor between o and 1 that is multiplied by the Size parameter of the Tri-Planar texture, the result being a random offset by an amount of factor x size in inches.
Is this correct?

The issue with this is that to achieve any visually interesting offset (that actually looks randomised when rendered in V-Ray), the Size parameter needs to be fairly high.
So with a plywood texture, for instance, which in real world is 3x3 meters, I would like to achieve an randomised offset of say 2.5m (100 inches). This means that I needs the Size parameter of the Triplanar texture to be 100, so that the offset will be [0-1]x100 = [0-100] inches.

The problem with this is that for the texture to appear at the correct scale in SketchUp viewport (3x3m), it needs to be scaled to that size in the SketchUp native material editor, specifying 3mx3m in the texture dimensions. The V-Ray triplanar size parameter then needs to be set to 1 to display at the correct scale.
but the resulting offset seems to then be only 1 inch (size x offset factor [0-1] = [0-1] inch, which is hardly noticeable when offsetting a 3m wide texture...

So the only way I found to achieve full random offset range for the TriPlanar texture [0-2.5m] is to set the SketchUp Material to a size of 2500/100 = 25mm (1 inch) and then have a Triplanar size parameter set to 100. That looks fine in Vray render but way too small in the Sketchup viewport (100x too small), unless I scale the UVs in SketchUp, but that is precisely what I was hoping to avoid with the Triplanar material...


Am I missing/misunderstanding something?
How can I achieve noticeable random offset on a triplanar material (ie with a range close to the actual size of the material) and still have a normally scaled material texture in the SketchUp Native renderer?

Cheers,

Thibaut

[Antioche]

No suggestion on this issue?

[konstantin_chaos]

So the only way I found to achieve full random offset range for the TriPlanar texture [0-2.5m] is to set the SketchUp Material to a size of 2500/100 = 25mm (1 inch) and then have a Triplanar size parameter set to 100. That looks fine in Vray render but way too small in the Sketchup viewport (100x too small)

You are exactly right here.
Unfortunately there is something we have overlooked - the Tri Planar texture should not be affected by the material size in SU.
This would sort of resolve the issue for you.
As an alternative we could modify the texture behavior itself so that the random offset accounts for the material size.
It's hard to explain what the exact issue is but we'll do our best to improve this workflow.

In the meantime you can try the following workflow:
1. Create a material with a triplanar texture and a bitmap
2. Copy the same bitmap in the Binding / Custom texture material slot - this one will be displayed in the viewport
3. Set the SU material size to 1m for example
4. Set the triplanar scale to 100
5. Set the triplanar bitmap Repeat to 100x100

Here's the result I get:


Regards,
Konstantin

[Antioche]

Hi,
Thanks for the suggestion.
That seems like a possible workaround, yes. I will give it a try.

A related question about TriPlanar:
If I apply triplanar randomisation to several texture map slots (diffuse, bump, reflection, etc.), would all transformations for each object be the same? I mean, would the bump triplanar texture, for instance, still be aligned with the diffuse triplanar texture?

Cheers,

Thibaut

[konstantin_chaos]

If I apply triplanar randomisation to several texture map slots (diffuse, bump, reflection, etc.), would all transformations for each object be the same? I mean, would the bump triplanar texture, for instance, still be aligned with the diffuse triplanar texture?

I believe so.
The randomization seed is the Render ID of the objects.
It'll match for all the material slots.