deformer | ACL 2020 ] DeFormer : Decomposing Pre | Natural Language Processing library

There's definitely lots of different approaches you can take to scatter objects on a surface. You can use geometry and normal constraints. There's MASH's framework. But I think using a follicle is easy enough and requires less overhead. The only catch is that the surface must have uvs as this is how we'll move the follicle around.

So here's what I'm suggesting:

1. Create a follicle, and connect it to the surface you want to scatter onto.
2. Create your grass object.
3. Each time you instance a new grass, pick a random uv for the follicle to pop to. This will align it to the face's position and normal.
4. Use the follicle's transform to move/rotate your grass to.
5. Rinse and repeat steps 3 & 4.

Here's a full example:

The reason the webgl canvas is blank has been answered at least 10 times here on stackoverflow

Saving canvas to image via canvas.toDataURL results in black rectangle

Canvas toDataURL() returns blank image only in Firefox

toDataURL() of webgl canvas returning transparent image

Why does my canvas go blank after converting to image?

I know there's several more but I'm too lazy to search for all of them

The only reason I didn't mark this as a duplicate is because you wanted 1 png from 2 canvases.

If you want just 1 png then you need to capture from one canvas. So, draw the WebGL canvas into the video canvas then call toDataURL on the video canvas.

About the direction:

I think your line : point += (Center - point) * bulgeAmount * w * env;

is a good starting point. But instead of using (Center - point), you should use its opposite, (point-Center) and normalize it before using it. If you don't use a normalized version of this (point-Center) vector, every vertex will be translated to a wrong position.

About your variation between 0.0 (original) to 1.0 (sphere):

If Po is the original position
If Pf is the final position
If d is the original distance between the point Po and the Center C: d=norm(Center - point) = norm(C-Po)
If Direction is (Center - point)/d (so normalized, as explained above)

What we want:
At r=0.0 your vertex must stay at its original position: Pf = Center + Direction * d

At r=1.0 your vertex must stick to the sphere of radius R: Pf = Center + Direction * R

And if we generalize:

Pf = C + Direction * ( r*R + (1-r)*d )

With d = norm(C-Po)
Direction = (C-Po)/d
R the radius of your sphere
and r a user param between [0.0; 1.0]

Not sure I am clear enough, I'm not used neither to answer here :) Best

You can use this node. You just have to loop sphere1 vertices to the inPosition value and getAttr the closestVertexIndex attribute : https://download.autodesk.com/us/maya/2008help/Nodes/closestPointOnMesh.html

but you will have to make both of your spheres to have the same center

another solution : another solution could be : if you have the same uvs on spheres, you could be transfering the weight by evaluating uv coordinate. Or even outputing a texture and sampling the picture to get values back on another sphere.

Just realized that you use "bend1.curvature" as attribute name, here it works if I use only the attribute without "bend1." as attribute name.