Parenting prop to specific geometry on a figure

jbrownos

I'm trying to figure out a way to basically attach a prop (or another figure) to where it move in relation to a specific part of surface geometry. As an example, let's say you wanted a small laser coming out of someones shoulder. There's a texture in a specific spot that needs to be aligned with the laser. If you simply map it to the shoulder itself, it won't necessarily be in the right place when it moves.

So I'm wondering if there is a way to somehow create a specific set of vertices or polygons that can be used as the parent. A surface group would work, as well, since they're based off of surface geometry. I'm not really familiar with how clothing works, but I'm wondering if that system might provide a solution. Maybe even collision detection might be useful.

As a last case scenario, I'm fairly experienced with programming, so I could look at scripting something. I'm not sure if the scripting libraries include something to deal with vertices, but IIRC, Poser had that ability in Python. The scripting documentation says it's similar to JavaScript, so it shouldn't be too difficult; however, I'd rather not have to spend time learning all the arbitrary commands for it if I don't have to.

Thanks to anyone who has any advice. I suspect there may not be an "official" way to do what I'm asking, but I couldn't even name all the times I've had to find some creative way to make software do things that weren't intended.

Pendraia

The old fashioned way of parenting should work. Just drag the prop in the scene tab and drop it over the area you want it parented to. This should parent it to that area. You will still need to position it (preferably on the zeroed figure as it's easier) how you want it but once done it should follow the figure.

fixmypcmike

You can also select the object and right-click on it, choose Parent to..., and specify the exact node you want it parented to.

jbrownos

I'm not sure I managed to explain my question well. I'm familiar with how to parent a prop to a node. What I'm needing to do is parent something so that it moves with specific polygons (or vertices) on a portion of the node's surface.

Parenting the object to a node in general will cause it to move only in alignment to the "bone" for the node. I'm needing something where it remains attached to one point on the surface (basically skin on a figure). If the skin bends, twists, etc. then the prop is no longer where it's supposed to be. The same occurs if morphs are applied.

Pendraia

jbrownos said:

I'm not sure I managed to explain my question well. I'm familiar with how to parent a prop to a node. What I'm needing to do is parent something so that it moves with specific polygons (or vertices) on a portion of the node's surface.

Parenting the object to a node in general will cause it to move only in alignment to the "bone" for the node. I'm needing something where it remains attached to one point on the surface (basically skin on a figure). If the skin bends, twists, etc. then the prop is no longer where it's supposed to be. The same occurs if morphs are applied.

Is it a weightmapped item that you are trying to do this with? If so maybe geografting would work?

Richard Haseltine

Or a rigidity map, if it's morphs you are trying to match.

Pendraia

Richard Haseltine said:

Or a rigidity map, if it's morphs you are trying to match.

Good thought Richard! I've been thinking about this (always a worry I know) Geografting is really designed for this exact purpose...it's meant for things that attach to the body like horns, wings and tails. Giving the added benefit of no gaps...the only draw back is we are still waiting in DAZ3D to clarify the terms of its use.

RKane_1

A nice tutorial would also be a nice thing to have even if only for our own private use....

Just sayin'. *smile*

mjc1016

There was a tutorial on the old forums...

http://forumarchive.daz3d.com/viewtopic.php?t=184183

jbrownos

The object I'm trying to attach is basically a relatively simple prop that I created in 3DSMax and imported. I have no idea how to do weight mapping for it, or even how weight-mapping works. I'm not really familiar with rigidity maps, and I thought they were mainly designed to affect how cloth, skin, or any similar surface could move or bend.

Based on what I've read, geografting sounds like it might be able to do it. It looks like it's mostly designed to combine some of the polygons from two objects/figures together, but it seems like it could be used to simply connect geometry in specific place without actually fusing it. I've looked at the (incredibly sparse and arcane) documentation for geografting, and I managed to get nowhere exceptionally quickly. I'm not ready to give up on it just yet, though.

These are the pages I've been looking at:

http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/terms/geo-grafting/start

http://docs.daz3d.com/doku.php/public/software/dazstudio/4/userguide/creating_content/assembling/tutorials/geo_grafting/start?do=export_odt

The second document says to "build a mesh that shares coincident boundary vertices/polygons with the host it is intended to graft to." I might interpret that as meaning that the attaching object has to have some identical geometry to the host figure; however, I'm really just not sure. That seems somewhat limiting, and you'd likely have to copy some of the host figure's mesh and try to somehow work it into the mesh for the attaching object. Worse still, forcing the geometry to match identically sounds like it would distort the base of the attached object when the host's surface bends.

Does anyone know if there's supposed to be more thorough documentation coming out at some point? I've noticed that a lot of the features for DS 4.5 don't really have any explanation on how to use them (or even what they do in many cases). I tried to play around with the scripting language, for example, but I couldn't find any information beyond a few sample scripts.

Richard Haseltine

A GeoGraft has to join to the host figure - if it doesn't there's no point in GeoGrafting. So you need an area that encloses the area you wish to change, and you duplicate the edge loop enclosing it and build your mesh in from that. When set-up and applied the GeoGraft hides the area of the original figure enclosed by the boundary, replacing it with its own mesh. I don't think this is what you want.

A rigidity map specifies that certain polygons should deform as a unit, keyed to a single polygon that is a logical anchor point for the item. It will scale and translate as DS auto-generates morphs, but only as the anchor polygon does - without a rigidity map each piece will deform to maintain its relationship with the nearest part of the figure it is fitted to. This affects only the auto-generation of morphs, it doesn't affect distortion from posing (which would be handled with weight-map adjustment), nor of course does it affect custom morphs created in a modeller. The attached images show a simple cylinder turned into a conforming figure - the first is what happened when I dialled up the morph on Genesis without any rigidity map, and as you can see the cylinder has distorted as it tracks the changes in the head shape; the second image shows what happens with a different morph after I created a rigidity map including all polygons and set the refrence point to be one of the top polygons, touching the lobe of the ear