Help understanding Geometry Switching

stitlown

Hi all,  I've spend a little time looking in the doco and in the forums, but I've not found anything I felt was useful to explain what "geometry switching" is and how to load it up on a model I have.  In my mind (wishful thinking??) I'm imagining it's a way to make a node use a different mesh, or a different shape of the same mesh for quick changes of appearance / function without / instead of using morphs.

As an example - say I have a sword model - but I want it to be able to be a long-sword, a short sword, a scimitar or a katana - either all variations on the one mesh (ie same number of vertices and surfaces) or maybe different meshes (different vertices and surfaces).  Can this be done by using geometry switching, and if so, where is some reference from which I can learn how to use it?

Thanks in advance.

Leana

Geometry switching was a technique used for Poser models where you could have different meshes for a given section of the model and switch between them with a dial. I'm not sure how it was setup exactly.

For models in Daz Studio format you'd probably use geografts to get the same features.

richardandtracy

If you mean something - for example - like having a hand, a hammer or a knife at the end of a custom model's arm, then there may be an alternative to Poser's geometry switching in DS... I think. I am not completely up with it, but I think this is how it would go:

Create the model with all the bits you may want to hide as part of the model (possibly intersecting - doesn't matter as only one will be visible at a time), but with each bit of 'hidable' geometry in a different group in the obj file you create before importing the model into DS for rigging. Make each different group into a different bone in DS along with the rigging used for the rest of the model. Then there will be a visible 'bool' button for each bone, just like with character's bones. In the root of your model, set up several ERC bools, each of which has its appropriate bone visible and makes the other 'switchable' bones invisible. It may be possible for a user to mess this up, I'd have to experiment, but I think the user would have to be determined to mess it up (in which case, serves them right).

If it's for a variable shape appendage for a current figure (eg G8/G9) then I think you would have to have the hiding bone idea above acting on a geograft model. The hidable bits of geometry would all be part of the geograft.

I'd be very interested to know if this does work..

Regards,

Richard

crosswind

You either can make it with Condition Graft modifier + geometry for long / short / different shape of swords, etc... or, as you saw in another thread, by using Boolean properties as Control Property of the different morphs of swords. It's up to you to make the sword as a Figure or a Prop... i.e. you don't have to need any bones actually.

The difference between the above two methods is that: 1) you need to set separate material zones for the different surfaces of the types of sword in the former; 2) you use the techniques of morphing rather than surfaces in the latter.

richardandtracy

Ahh. So the bool makes surfaces visible instead of making bones visible with 1), and 2) just switches morph settings on/off. Makes it less complicated if you don't need rigging.

Thanks for that, Crosswind. Hope I'll remember when I want to try it out.

Regards,

Richard

crosswind

richardandtracy said:

Ahh. So the bool makes surfaces visible instead of making bones visible with 1), and 2) just switches morph settings on/off. Makes it less complicated if you don't need rigging.

Thanks for that, Crosswind. Hope I'll remember when I want to try it out.

Regards,

Richard

Yea, exactly as you said. 

stitlown

Thanks all.  So my takeaway from this is that "geometry switching" is either not relevant or no longer the best solution, and the two alternatives are:

1. A more complicated mesh which covers all variations wanted and has different surfaces for each variation + bools to switch surface visibilities on or off; or
2. morphs tp reshape a mesh to the different variations, perhaps with bools and hiding the underlying morph to make any variation and on or off affair.

I suppopse the key thing to note is that for option #2 all variations have to share an identical mesh structure (# vertices and # surfaces), and that UVs might end up a bit distorted (but that could be rectified with alternative UV sets, whilst with option #1 the modeler has free reign.

Cheers, Lx

crosswind

I personally recommend option 1 which is much easier and can bring you much better results... if you want to make a "modular Prop".

stitlown

stitlown

Oh dear! Once again, it appears there's something I just don't understand.

So I've been able to achieve what I needed to (yay team!) but to do so I had to set the model up as a figure - both because conditional grafts appear to only apply to figures, not prop meshes, and because I could only see one way outside the geom editor and eg surface opacity to make anything visible / not visible; which required the mesh to be split up into bits assigned to bones.

So where outside the geom editor or the surfaces tabs (neither of which can be controlled by "properties", as far as I can see) can one set a surface or a face or other mesh subset defined in the geom editor to be visible / not visible separate from the scene tab / parameter tab visibility property for the entire mesh?

crosswind

Not sure what you want ... Face group assigned to a bone, then hide the bone so as to hide the face group ?

stitlown

Thanks crosswind - I was wondering if there's a way to do the (say use the sword example from earlier) multimesh bool up different views of the mesh without making the multimesh a figure.  ie is there a way to toggle visibility of various surfaces in a mesh (via properties booleans) without making the mesh a figure with bones and assigned face groups (where it is possible to toggle visibility via the bones).

crosswind

Well, you can make them as multiple Props and group them together... rather than making a single Prop. Like the way that PA censored used in this product: https://www.daz3d.com/the-shoguns-armoury

Then you can control Visibility of each part (Prop) in Parameters pane, even create some control properties on the Parent Prop with ERC links to toggle Visibility of its Children Props.

stitlown

Thanks, Crosswind