Posebased Deforms

[sanostol]

I want to use blendshapes to correct my captured geometry in extreme poses. How can I use the morp tool to shape this modifications on the deformed mesh, for example the arm is bend to it's extreme and I want to shape in some volume back and some other stuff, but as soon as I start shaping with the morph too the display flags are set before the deformation. is there a way to create shapes on top of the mesh and the blendshapes are calculated what they would be without deformation?

martin

[sibarrick]

There's an hscript command called "sopcreateedit" which will compare two models and create an edit sop that contains the difference between the two, this can then be used with blendshapes in morph mode. Does that help?

[sanostol]

I guess not, cause it would also contain the modifications of the bonedeformer and applying this as a blendshape previous to the bonedeformation would result in a doubledeformation. but maybe the script can calculate what the edit must contain without the bonedeformation.

It's hard to explain so another example:

a armgeometry is captured to bones.

the bones bend the arm and this causes the geometry to loose volume

take a snapshot of the deformed geometry

reshape the geometry so it looks right again.

from this new geometry I want a shape that does not contain the pointmodifications of the deformer, but only my edits. so when I blend it in in the exteme pose it looks like the shaped one.

some tools even allow You to modify on top without creating a new object

I will look at the hscript maybe it allready has this ability

thanks

martin

There's an hscript command called "sopcreateedit" which will compare two models and create an edit sop that contains the difference between the two, this can then be used with blendshapes in morph mode. Does that help?

27818[/snapback]

[edward]

Here's a contrived example. Try this:

1. Load attached hip file. Make sure you're at the object (blue) level.

2. Scrub on the timeline to observe the shapes I've already done on this file. Notice how the shapes work with the bone angle even though the bone chain is being rotated.

3. Go to frame 40 where both shapes are in full affect.

4. In the object viewer, Tab > Morph. Select the tube geometry object first. Then select three points at the top of the bulge, right-click to finish.

5. Hit 'p' in the viewer to bring up the Morph tool's parameters.

6. In the Tool Dialog tab, (or in the normally collapsed operations controls toolbar at the top), choose Layer > bulge.

7. Move the transform handle in the viewport up to exagerrate the bulge.

8. Scrub to see how the bone chain is animating. Tweak the handle at any frame when moving up and down. I think it's a bug that the handle doesn't follow. I recall it working back in Houdini 6 or 7.

The magic all happens inside the /obj/geo1/blendshapes subnet. Notice how the blend expressions of the /obj/geo1/blendshapes/blendshapes1 are based on joint angle. Note also the use of the second input of the Edit SOP so that the edits are relative to the shape pre-deform.

morph_setup.hipnc

[sanostol]

This is great, thanks for this example, it cleared so much. I wanted it to do it the non-houdini way, my fault.

martin

PS: it's better than I expected, hehe.

[sibarrick]

Looking at the help for the morph tool

Shapes created with this tool are blended into the original geometry. The blend factor for the current shape can be manipulated with the provided HUD slider.

Is this broken?

[sanostol]

No, it was me.

Looking at the help for the morph tool

Is this broken?

27824[/snapback]

[edward]

The HUD sliders look like they were removed a long, long time ago. I've now fixed the docs.