Mystique Transformation - Geo Morph by texture

[andyhowell]

Does anyone know of a way to morph/blendshape geo using a texture.

 

I came across this

 

https://hdbp.io/BjGNeLeB

 

Which was along the right lines. 

I'm wanting to use an image sequence to weight the blendshape of one geo to another. I understand the geo will need to match in terms of point order.

There was another interesting method in which there is a morph between VDB's which again was great, but only allows a volume alpha mask to control the blend.

Any ideas would be appreciated. I did use Stroika, a plugin for Maya years ago that did the job perfectly.

 

 

 

[mestela]

Here's one of no doubt many ways to do that effect.

blendshape_from_ramp.hipnc

[andyhowell]

Many thanks for putting that together. Works really well.

I'm now going to see if I can blend between objects with the same topology but different models. 

I can see how the ramp works to affect the inflated version of the mesh.

I need to run a texture sequence through this input instead, using UV's of the models.

Great starting point though, thanks again, I'll keep you posted on where I get to.

Thanks.

Great Wiki by the way.  

[mestela]

Yep, you can see I'm creating an attribute with a wrangle and ramp like the stroika video you linked, but you could use an attribute-from-map to make that attribute from an image sequence. 
 

 

[andyhowell]

Yes, got that going earlier today.

I'm new to Houdini, I've been an effects TD at various film post houses, but only on Maya.

Really like the workflow. I've also been going through some of your Wiki site. Really great explanations. Thanks very much for your help.

I've been out all day, but planning on getting something together this evening. I'll keep you posted. I managed to get an Alamebic file in from Maya. I saw that there are UV issues with the transfer, so needed to apply new ones, also there was the whole unpack node I had to add to allow for changes. I have a lot to learn. Frustrating but exciting.

Thanks again

Andy

 

[Aizatulin]

Hi,

here is a reduced version of matt's example.

The basic idea behind:

• take two objects (A,B) with same topology (if the topology does not match, there are methods to achieve that -> for example xyzdist() calculates the closest distance from a point to another geometry)
• the next step is setting a @blend attribute for object A for each point (there are many ways to do that -> you can use functions like ramps, noise, maps etc...)
• now you can use the lerp function (linear interpolation) to blend between two correspondings points of A and B (they should have the same @ptnum)

In my example I have used a noise function and the attribute from function to set the @blend attribute. You are totally free how to set this attribute, but the value should stay between 0 and 1.

I used attribute wrangles, but they have only a few lines of VEX-Code.

blend_with_attribute.hipnc