Follow Displace Surface (V-Ray) problem

[Ricousto]

Hello

I have a forest for grass and other things on a terrain.
My terrain has a VRayDisplacement. This VRayDisplacement is a composite map with 2 maps and a vertex colour as a mask (see attachment).
I use Follow Displace Surface (V-Ray).
So far so good, but when I instantiate my composite card, the effect doesn't work. My grass doesn't follow my displaced surface.
If I just put in the map without the vertex colour mask, everything's fine.
Is this a limitation of this effect?

Another question:
Is it a problem if I use Texmap min: -1 / Texmap max: 1?

Thanks

Best regards

[Michal Karmazín]

Hi,

You should avoid using the VRayTriplanarTex map. Once removed, it should work just fine. As for your second question, there's no problem with setting Texmap max to -1.

I hope that helps.

Best regards,

[Ricousto]

Thanks for your answer.

The fact is it work with triplnar but not with the vertex color mask.
It seems that the problem is more about that mask.
But I really need that mask !
Could you please, give me some advices ?

Thanks

[Ricousto]

I found that topic https://forum.itoosoft.com/forest-pro-(*)/vraydistancetex-used-as-mask-for-displacement-not-working/
Is it the same issue ? is it similar in some way ?

I'm still struggling with this problem

[EQ4593]

i am stuck with the same problem.
i have uploaded a stripped down max file (ref1.zip) with wetransfer for you to look at. the forest items are not following my base surface as it distorts with displacement using a composite of 3 different vraydistance tex materials.
 

[Ricousto]

It's a little different, I don't use VrayDistanceTex but a vertex paint as a mask between 2 displacement maps (composite).

The fact is that the grass in my forest pack has an offset above my displaced surface equal to the amount of VRayDisplacement when I use the composite map.
When I only use my displacement map without the vertex paint mask, the forest pack grass moves closer to the displaced surface.

Any advices ?
Many thanks

[Ricousto]

Bloody hell!
You're right, VRayTriplanar doesn't work with VRayDisplacementMod! (at least not with my old version of Vray!).
So I tried without VRayTriplanartex but keeping my configuration (Composite with 2 different maps and a vertex paint mask).
Unfortunately, I still can't work out why Follow Displace Surface (V-Ray) doesn't work!
Please find attached a simple scene

What the hell ? Please, can you help me ? What am I doing wrong ?

Thanks a lot

[Michal Karmazín]

I'm sorry to hear you're still experiencing issues with it. The used effect is designed to be used in UV mode (evaluating the fpItem.distUVW values). If you prefer to use XY Surface mode, you can replace it with fpItem.position. This should work just fine.

Please find attached the modified scene (240429_followDisplacedSurface_iToo.max). I hope that helps.

Best regards,

[Ricousto]

Thanks a lot

Sorry but I can't open your file, I'm working on a very old max

[Michal Karmazín]

In such a case, you can easily edit it yourself. In the Effects Editor window, replace 'fpItem.distUVW' with 'fpItem.position', as shown in the attached screenshot. I hope that helps.

Best regards,

[Ricousto]

Thanks a lot
I will explore that !
Thanks again

[Ricousto]

Hello
Sorry, but as you can see, it didn't work.
Maybe I've misunderstood something, but I'd really like to know if it's possible to use this effect in this context or not.

1-without VRayDisplacementMod
2-with VRayDisplacementMod
3-VRayDisplacementMod AND corrected Follow Displace Surface (V-Ray) - from replace 'fpItem.distUVW' to 'fpItem.position'

Thanks again

[Michal Karmazín]

Please double-check if the FP object's gizmo is located at the center of 3ds Max's World coordinates. If it is, would you mind sending us your scene? Thanks in advance.

Best regards,

[Ricousto]

Please double-check if the FP object's gizmo is located at the center of 3ds Max's World coordinates. If it is, would you mind sending us your scene? Thanks in advance.

Best regards,

I've just sent the scene
Thanks a lot !