MASH problem: instance orientation with world node gets reset

[Anonymous]

New to Maya and MASH so bear with me please. 

Adding instances to a surface using MASH. Distribute some instances using a Placer node, and they are snapped to the surface mesh perfectly (Y up, relative to the surface normals).  However, when I add a World node to create some clusters around them the seed instances re-orient so they are all pointing Y-down in world space.  See attached pic.

The clusters created by the world node align to the mesh, but not the source objects. Very irritating.  I can sort of fix it with an Offset node above the World node, snapping everything to nearest face, but then I lose the ability to rotate and move the original placed objects properly.

Am I missing something?

Thanks in advance

[sean.heasley]

Hi @Anonymous 

Ah ok I see the issue. Yeah there does appear to be an issue with the random rotation tool for the placer node that I'll pass along to development.

That said, if you use the actual random node and have it above the placer node does that work for you in terms of random rotations scale etc?

[Anonymous]

Unfortunately not. Either the rotation is locked out, or I am able to
rotate only in uncontrollable angles, so the objects are not aligned with
the mesh (I think it's shown in one of those clips). I tried creating some
random rotation anyway, and using another offset node on top to snap them
back into place, but the Offset node just resets the orientation back to
straight up again, killing all the rotations.

right now I think the only way to get random (ish) rotations would be to
make multiple copies of all the instanced geometry and create rotated
versions, and add those to the MASH network. That is pretty cumbersome
though.

[sean.heasley]

Hi @Anonymous 

If you're on a time constraint that may be your best bet but I'm actively looking into this its just tough to get the specific setup you want.

[Anonymous]

I appreciate your time and effort on it.  If the rotation thing gets fixed then the whole thing will be a lot easier for sure!

/b

[sean.heasley]

Hi @Anonymous 

Just looking at other options while messing around with MASH.

Have you tried using particles like in this video?

[Anonymous]

Thanks for the link. I have not tried that exact approach in Maya - the expressions/script-y part is over my head, but I have tried a test with nParticles for placement, and I have done very similar approaches in Max using Particle Flow, and also with Real Flow.  It looks okay at lower res, but it just doesn't hold up for really detailed renders at 6k-8k (IMO) and it lacks the control that we tend to need to make art directors happy. That is why I ended up using scattered geometry. 

My best results in the past were done using tools like ForestPack in Max - that's the workflow I'm trying to rebuild here.

[sean.heasley]

Hi @Anonymous 

Darn I was hoping that would help.

I totally get where you're coming from and it completely makes sense why you would want as much control over this as possible so you can get the desired look.

I can't 100% tell if this may be a limitation of MASH or if we're both just missing something that would solve it. Therefore I just sent an email with this thread to two of our MASH gurus so they can take a look at what we've been doing and let us know what the next best step to take is. I'm hoping to get a response by the end of the day but if that doesn't happen I'll be sure to update this thread Monday as soon as I hear back from them!

Sorry this has been taking so long and that we haven't found a solution yet but I'm hoping this will be the last big step we need! Thank you for your continued patience with this !