I was wondering if there was a way to blend-shape between two objects (morph) that have totally different topology. Would I be using a Point sop to map the points from one object to the other? And if so, how?

Thanks in advance,
markerline

Hi there

as far as i know it is not possible to use the blend tool on geometry with different topology

regards

erik

Thanks for your reply. Just wondering how they did the Olay “Total Effects” Syrem commercial where the Olay bottle (with the top that looks like a penguin's beak) transforms into a flashlight and a lock and a few other items.

-markerline

markerline
Thanks for your reply. Just wondering how they did the Olay “Total Effects” Syrem commercial where the Olay bottle (with the top that looks like a penguin's beak) transforms into a flashlight and a lock and a few other items.
-markerline

There is a mix of techniques you can apply to achieve such effect. AttributeTransferSOP works great on arbitrary different geometries, but relies on distance factor. Combining it with UV space attribute transferring could cut off this limitation and gives you better control on morphing. There is also BlendPose CHOP which could help in solving some local issues (I don't think it can carry a whole mesh).

1. Transform your both geo's points into uv space (with PointSOP for example)
2. Use Attribute Transfer SOP to copy P from one onto another.
3. Transform back geometry to Cartesian space.

This is a first and naive way of doing it. Most probably you will have to tweak details. Things like morphing speed could be effectively controled in CHOPS by blending pre- and post morphed mesh based on some attribute.
All of this greatly depends on a kind of your geometry. Morphing sphere to cube is a piece of cake, but shapes like humans or trees could be more difficult.

hope this helps,
sy.

1. Transform your both geo's points into uv space (with PointSOP for example)

Sy this is very helpful info but I am not sure where to begin with the Point SOP for converting T info into UVs. Am I to use the $MAP texture attribute? Or am I to place an expression in the point position attribute? I discovered that P is the attribute for position (not sure what Pw is just yet). Once I do that I guess it will be easier for me to figure out how to get UVW space back to XYZ space.

Thanks in advance,
markerline

This is the file that I got so far. I've templated a sphere and tried to match a box to it just to keep things simple. For some reason I can't get the overlapping points to find their way to the “unused” points of the sphere. So I appended a clean sop to get rid of them.

-markerline

Here's something silly I came up with. In theory you should be able to blend any shape to any other but it's not efficient at all. (maybe holes wouldn't work, not sure)

There's a blend slider in the volumemix1 node.

The quality isn't very good though. There must be a setting somewhere.

edit: Actually, setting output type to SDF Volume gives much smoother results

markerline
Thanks for your reply. Just wondering how they did the Olay “Total Effects” Syrem commercial where the Olay bottle (with the top that looks like a penguin's beak) transforms into a flashlight and a lock and a few other items.

-markerline

it's very likely that the geometries were /exactly/ the same…then it's a simple matter of using a blendshape…

In response to Sy's original idea, I figured out what I was doing wrong in the file I uploaded. Even though I had used a resample sop to increase the number of points to more closely get in range of the sphere I was blend-shaping to I hadn't subdivided the box to increase its primitives and thus the blend shape could not perform properly. What needed to happen is that the Box had to have more geometry than the Sphere. In other words one has to have more than the other and then it's a matter of blending in the right order from least geometry to greatest (if this is making any sense).

In response to Soothsayer's file that is a very interesting concept and it does work with a little tweaking. I was able to blend between a simple end-table geometry and a highly simplified flashlight–four legs to a simple revolve. That was magnificent.

Finally, arctor's point is well-taken, but it brings me back to my original question–How could one model such different objects with exactly the same geometry without running it through some kind of parsing program or Houdini to match the topologies? I guess someone must have written a proprietary plugin to say resample object A to have the same number of primitives (faces) and points (vertices) as object B and do the same for all objects in the scene. Wow.

Thank you all for your knowledge.

-markerline

unlikely…they just do a lot of modeling….
look online for articles about the Mystique transformations in X-Men

Has anyone made the morphing with conversion to UV space like in SYmek's post?

there is a tool named UV ShapeBlend on exchange