Thanks, arctor! bug reported to Houdini.

The attached file runs smoothly in Houdini v.12, but it always freezes when running in Houdini v.15, and it seems it only happens when the paint node is added.

Can the Houdini developer help to check if this is a bug?

Thank you!

I want animate a group of points moving from their original positions based on the vector and velocity values embedded for each of them.

However, I have the following problems:
1. there is always a point at the original position which I don't want.
2. each point will stop after moving for certain distance even if I used a delete node to “kill” it based on its life span.

I'd appreciate your suggestions to solve this two problems!

Thank you!

may I ask how to visualize primitive attribute in scene view in Houdini 14?

I just don't know how to use the latest “visualize” bottom with all the marker or color option …

It seems the particles reaching the max lifespan around a spatial boundary will stay there rather than been “killed”.

May I ask how to get rid of the particles from the scene based on certain criteria so that the total number of particles will not keep increasing?

Thanks!

(mentioned in the following post, too)
https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=37818&sid=d06f2f24f29698d38c376c0d7936a15d [sidefx.com]

… update

thank you very much, pezetko!

Learned a lot from your advices!

sorry, I found my python approach did work, but a fuse node is needed to merge the overlapping points generated in the process.

Moreover, I found that PradeepBarua's approach may not work when try to get the max number of lines between all the points, e.g. there are 45 lines btw 10 points maximally… Can PradeepBarua kindly check and advise?

BTW, the popnet node is to animate the points which gives interesting results, and pls try out by using the delete7 node as input!

One problem is that I don't know how to “kill” those points reaching their life span which stop at the outermost region ….

Thanks, PradeepBarua!

Can you and friends here also kindly advise why my python approach shown above doesn't work?

Thanks a lot!

… minor update of the approach that is not working ….


node = hou.pwd()
geo = node.geometry()

geo_ref = hou.node(“../scatter1”).geometry()

# Add code to modify contents of geo.
# Use drop down menu to select examples.

points = geo_ref.points()
num_pt = len(points)

Matrix = [ for x in range(num_pt)]

cnt = 0;
for pt in points:
print “point”, cnt, pt.position()

pt_pos = pt.position()

cntt = 0
for ptt in points:
ptt_pos = ptt.position()

# get the distance between pt and ppt
dist = pt_pos.distanceTo(ptt_pos)
print “dist btw pt”, cnt, “and pt”, cntt, “is:”, dist

connected_or_not1 = Matrix
connected_or_not2 = Matrix

# if the distance < threshold of 0.5
# and if the connection betwee the pair is not marked as “connected”
# then draw a line between pt and ppt
# and mark this pair as “connected”

if dist <= 0.5 and dist != 0 and connected_or_not1 == 0 and connected_or_not2 == 0:
print “draw a line btw pt”, cnt, “and pt”, cntt

line = geo.createPolygon()

l_s = geo.createPoint()
l_s.setPosition(pt.position())
line.addVertex(l_s)

l_e = geo.createPoint()
l_e.setPosition(ptt.position())
line.addVertex(l_e)

Matrix = 1
Matrix = 1

cntt +=1

cnt +=1

Thank you very much, Pradeepbarua!

Grateful if you can share the VOPs solution!

I'm trying to use the following Python node to do it, but I still can't get it working and no line is drawn …. Appreciate if you can take a look and point out the source of problem of my approach!

# geo_ref node is the one with all the points
# geo node is the one to which all lines will be added
# I use a 2D array to register if one pair of points is already connected

node = hou.pwd()
geo = node.geometry()

geo_ref = hou.node(“../scatter1”).geometry()

# Add code to modify contents of geo.
# Use drop down menu to select examples.

points = geo_ref.points()
num_pt = len(points)

Matrix = [ for x in range(num_pt)]

cnt = 0;
for pt in points:
print “point”, cnt, pt.position()

pt_pos = pt.position()

cntt = 0
for ptt in points:
ptt_pos = ptt.position()

# get the distance between pt and ppt
dist = pt_pos.distanceTo(ptt_pos)
print “dist btw pt”, cnt, “and pt”, cntt, “is:”, dist

connected_or_not = Matrix

# if the distance < threshold of 0.5
# and if the connection betwee the pair is not marked as “connected”
# then draw a line between pt and ppt
# and mark this pair as “connected”

if dist <= 0.5 and dist != 0 and connected_or_not == 0 :
print “draw a line btw pt”, cnt, “and pt”, cntt

line = geo.createPolygon()

l_s = geo.createPoint()
l_s.setPosition(pt.position())
line.addVertex(l_s)

l_e = geo.createPoint()
l_e.setPosition(ptt.position())
line.addVertex(l_e)

Matrix = 1

cntt +=1

cnt +=1

suppose I have a group of 50 points, how to draw lines between each pair of points based on a distance threshold?

something like the following:
http://albertomoss.com/img/med/googlewallpapers_med_0002.jpg [albertomoss.com]

I couldn't think of an easy way to do it using the default geometry nodes…

I assume there might be a generic algorithm to do this, something like:
1. draw lines from a point to all other points within certain distance
2. remove the above point from the point list (this is to avoid duplicated lines between a pair of point)
3. repeat step 1 for a point in the updated point list

But, I don't know how to do it using python in Houdini…

Thanks!

May I ask how to find the centroid of a 3d geometry, such as a box?

Thanks!

well, I found that the same model imported as obj file poses no problem to the use of my python node. So, I assume it's probably a .bgeo file format issue …

anyway, additional advices are appreciated!

I imported a bgeo geometry and use a python node to write out each polygon's centroid position and normal. However, I got the error message that “Surface” object has no attribute “normal”.

What I don't understand is that I can see the normal lines when I turn on surface normal display. And the same python node works fine with other polygons created in Houdini.

May I ask how to get the normal back?

Thanks!

The ink effect imitating traditional Chinese painting is amazing as shown in the opening sequence of the latest Marco Polo TV series created by the Mill:
http://www.themill.com/work/marco-polo-main-titles.aspx [themill.com]

I wonder how it can be realized in Houdini. Maybe expert here can share some ideas.

Thanks!

I want to export an obj file with the all the current basic colors of the primitives or ambient occlusion baked as surface texture or basic materials.

I want import the obj file into Unity with all the color for each surface intact.

May I ask how to do this in houdini?

Thanks!

any advice?

Thank you very much!

I installed the following:
Houdini Apprentice Houdini 13.0.615 (64bit)
Unity 4.6.0 (free)

According to the guide on the following page:
https://www.sidefx.com/index.php?option=com_content&task=view&id=2739&Itemid=381 [sidefx.com]
… I created a new project in Unity, and go to Assets –> Import Package –> Custom Package –> C:\Users\Public\Documents\Unity Projects\Houdini_Engine_Project_13.0.615

However, there is no such file as "houdini-engine.scripts.unitypackage“ in the folder. There's only one folder ”Assets“ with four sub-folders within it, ”Houdini“, ”Houdini Script Access“, ”OTLs“ and ”Resources".

Can anybody advise what I'm missing there?

Thanks!

Thanks, Doodlez!

I updated my method, too. So, we have two ways to do it via the hscript in the “ctl1” node to drive randomness:

1.
int(rand(prim(“../each1”, 0, “id”, 0)+$F)*10)%4
… which gives you a random integer between 0 and 3 for each frame.

or

2.
int(rand(stamp(“..”,“FORVALUE”,0)+$F)*10)%4


Pls kindly advise if there are other efficient way to do this.

Thanks, again!