Hi!

I've got a model and on this model I've got a lot of black and white areas (Cd params in points).

How could I smooth them (but not manually - without paint sop) - It is possible to smooth (blend) these values a little bit with vop sop for example?

I would like to have control over the scale of blending (how much these colors would blend and how many neightbours we concider to blend)

Any tips will be welcome!

Thank you

Edit: I've managed to make something simmilar to what I wanted - I've created point sop, added normals, then I added peek sop - this created a “bigger mesh”. After that I transfered point colors from this bigger to smaller mesh, what made these colors blurred.

Is there any method to make this process faster? (with vex / vop)?
(the hard part for me is to find FAST the naightbours of a point (not to check every point in space).

Thanks

Oh I found a smooth sop to smooth colors

But can we make this with vex? (vop vex sops)?

1. Smooth SOP(sic!!!)
2. VOP-> Point Cloud ->pcfilter
3. CHOP -> Filter Chop -> Blur
4. Attribute Transfer SOP -> same source and target
5. www.houdinitools.com -> Attribute Blur SOP

Choose one!


EDIT:

Fast searching of points in space it's a second name of point clouds, since they are kdtree essentially.

If you are doing it in vops and want similar behavior as the smooth sop I would recommend to only “smooth” the connected neighbours, otherwise you will smooth over distance in space instead of over topology.

SYmek, pclaes, thank you for replies

SYmek -> My first way of smoothing was your's number 4, then I discovered that smooth sop can smooth a lot of things (heh ;P)
I was thinking about point clouds, but I wanted to smooth over topology, as pclaes tells ;]

Can we use point clouds to do this kind of behaviour? to fast search all points and measure the length “topologically”? So we will get fast all points that are near our searching point but they're not “near” in sense of space, but in sense of length of way on surface?

Yours point 3. looks interesting too - could you please tell me if we can smooth attributes with chops only in “neighbours” points?

And point 5 is great Thank you very muh! I've forgot about these tools and I think this is a big “knowlege book” I should check in some time

Thank you

danilo2
Can we use point clouds to do this kind of behaviour? to fast search all points and measure the length “topologically”? So we will get fast all points that are near our searching point but they're not “near” in sense of space, but in sense of length of way on surface?Yours point 3. looks interesting too - could you please tell me if we can smooth attributes with chops only in “neighbours” points?

Both can be achieved by computing blur in uv space, where topological coherence becomes spacial one

Thank you SYmek!

I didn't think about it asit is in uv space!
I need to do some tests I think

Thank you once again!

SYmek
Both can be achieved by computing blur in uv space, where topological coherence becomes spacial one

Hmm, interesting, this will probably be the fastest solution in a lot of cases as you can make use of the pointclouds. But what about seams? Or how do you lay out your uv's?

If you were to go without the pointclouds it would become much slower as you use a for loop to loop through the number of connected neighbours and average out the attribute with the current point. You can mix in the distance to the neighbour as a weight, but it would still only represent “one level of smoothing”. You can perform this operation several times by putting the operator in a foreach, but it will get slow.

You may be able to do it all in vops and compute the above for loop several times, but that will also be computationally expensive.

I just thought about the seams a bit more. If you manage to lay out your object into a square. Then you can probably copy it another 8 times and postion it all around to make it “tileable”. It would be quite expensive as you would perform the operation on an extra 8 copies (although you could clip those against the radius of the blur, so if the blur is small it would only be small number of extra points).

Kind of like this, where “O” is the original geomemetry transformed into UV space, and the “x”s are the clipped copies.
x x x
x O x
x x x

Afterwards delete the copies and transform back.

Modulus?

jacob clark
Modulus?

with pointclouds? Not if you want to make use of the pcfilter. The problem is the edge points, the pcopen will not take the correct points (the ones that wrap around to the other side) into account if you are sampling the “10 nearest points”.

I think modulus would work in the shading context when operating on the uv of your surface, but inside a vopsop?

Ahhh, I see your logic is sound.

Though, you could open EVERY point on the Point cloud in the PCFilter (per Point) to get away w/ the Modulus… Not sure which would be more efficient, 8 copies, or all Points.

I am curious to see what you create danilo!

-j

I tried writing a smoothing algorithm that takes topology into consideration. While it is possible it is extremely slow (Python). I calculated length by going via edges.

If you use UV then one problem could be that your UVs do not have a nice and blur friendly metric: distances may be distorted and you can have seams (?).

I haven't found a really good robust way via scripting yet, but I think the attribute transfer may do that best then.

Hehe Thank you very much for replies! This is really interesting topic

I'm wondering if it is somehow possible to use pointclouds and get somehow the seems problem around. I'll think about it in several days, becouse now I've got plenty of work ;]