Vray Triplanar and Next GPU is all over the place

[nick_martin]

The triplanar map is just all over the place with Next GPU.... if I plug a standard bump map into the triplanar map and make the blend 0.0 and then compare how that looks to the bump map just going straight into the bump slot. (ie no triplanar at all)... it looks completely different.

The scale is all messed up....

Can't even use triplanar as it is so unreliable and doesn't work properly in so many situations.

Can you guys have a look into it... its got a lot of bugs.

[matanov]

Please give me some examples. Is it different from V-Ray Next (CPU)?

[nick_martin]

Hi Peter, will render out some examples for you tomorrow.

[nick_martin]

So I rendered out a very quick test to show what is happening...

First image is a standard vray mtl with a concrete bump map going directly into the bump slot. Bump map is set to a real world scale of 300cm in the bitmap parameters.

.

And this is the exact same vray mtl with the bump map now going through a triplanar map (triplanar map is on defaults....blend 0.1 but get the exact same result with blend on 0.0).



As you can see the bump map is much much stronger when used through a triplanar texture.

Why is this? I would assume that if the triplanar texture where set to a blend value of 0.0 the result should be exactly the same as if there was no triplanar map at all.... except for different alignment of UV coordinates.

[chadstevens]

The Triplanar Tex has it's own scale setting, you need to adjust the scale in order to match your required results.

[nick_martin]

The Triplanar Tex has it's own scale setting, you need to adjust the scale in order to match your required results.

Makes no difference if you change the scale in triplanar or in the bitmap. The scale should be the same.

And this doesn't account for the complete difference in the look between the 2. It almost looks like the triplanar map is inversing the bump map or something....

Plus I don't want to use the triplanar scale settings as there is only 1 size which implies that the map is square.... I have asked chaos to look into being able to specify a width and length for the triplanar but that is another story

[chadstevens]

The scale should be the same as what? The scale default in the triplanar map depends on the unit scale and is generally never the same as just plugging the map straight into the material, you will have to adjust the scale to match the bitmap output you require.

See attached

No Triplanar/default map into material
Triplanar Added

Zoomed in on that Triplanar

Corrected the scale of the triplanar

[chadstevens]

As for the length and width scale, as far as I know it wouldn't make any sense to have that on the Triplanar tex, the Triplanar tex basically acts like a box uvw map with blended seams, it takes the aspect ratio of the bitmap and repeats it around the object, so the length and width will need to be adjusted in the bitmap and then the Triplanar will array that texture using it's blended box map mapping.

[nick_martin]

Cheers for investigating Chad. Using real world scale mate.... So I meant the scale should be exactly the same if it is stipulated in the bitmap parameters or in the triplanar parameters (assuming using a perfectly square map 1:1).

I don't think its the scale that is the main problem anyway.... its the completely different results of the bump map when they should be pretty much identical.

[matanov]

Hey Nick,

I'll check what's going on and update you all here in the thread as soon as I have more info.