Hi everyone,

I am building the effect of a waterdrop running on a vertical surface (bottle or whatever). I have curve as path and we raySOP I project it to the surface. Using a portion of the curve to running from the top to the bottom but what I want to be able to animate the speed, or even better using the speed mask based on surfaces normals at Y.

In the attached hip I have a test-setup with a vertical surface with noise and speed mask on its color. Wherever is black drop should travel faster and wherever is white slower. I am using two different techniques for the travelling of line with a switch. Any ideas?

Thanks in advance!

EDIT: What I am using for travelling the line is a duration, let say in 200frames finish the ride, but what I want to have is a constant speed and then be able to multiply this with an attribute as the speed mask. I would like to keep everything in SOPs if possible but I am also considering POPs.

zarti
havent downloaded previous suggestions

, but here it is what do in similar cases ..

–

!! it is a H11 file

hope it is ok for you .



.cheers

Do the skin after!!! amazingly simple and it makes so much sense. Sometimes when the answer is in front of your face you are missing it.

BUT when you have multiple backbones as input to the sweep and do the skin after, its gonna skin them as one unit. If each backbone has the same number of points then you can use the “N” parameter on the skinSOP comes, use the Groups of N primitives and use as number of points that a single backbone has. If you have uneven backbones as in my case then you cant use it.

I have attached a file which demonstrates the problem mentioned above.

rafaels thanks for the reply, to use the copySOP in a loop was my backup plan but I though if color could be transferred successfully then probably somehow other attributes can, but I guess I was wrong. @anim posted a workaround in the odforce forum, using the sweepSOP.

http://forums.odforce.net/index.php?/topic/16704-keep-backbone-attributes-when-using-sweep/ [forums.odforce.net]

Hi all,

I have a simple question with maybe not possible solution.

I would like to keep the point attributes from the geometry which is used as a backbone in the sweepSOP. By default, sweep will deleted all the attributes of the backbone but I noticed that succesfully transfers the color to the new geometry.

Is there any way to trasfer custom attributes?

If there was only one attributes vector attribute or three floats I could assign them to the color and then following the sweep I can break them again to individual attributes but I have two vector attributes.

Also attributetrasferSOP can do it successfully when the geometry is like the example in the attached file. Finally I can't use copySOP or polywireSOP because in my original scene I have multiple backbones merged and only sweepSOP gives me the right result by treating each backbone separately.

what would be the input of the ramp?

Thanks graham, I was hoping for your reply.

nothing?

I want to create a procedural cable mess which is working fine but the tricky part is to fix procedurally the intersection of the cables when they are close. I have attache a complete example of my cable mess setup which includes my attempts to address this problem.

I am using two loops, the first loop in every cable carve and the second in every point of the current carve (loop in a loop). Then each point using a point cloud the points of the other carves in order to find the nearest point, its position and the distance from it. In a second vopsop I am using these info to find if the distance is less than the radius*2 of the cable then move equally the two points away. The right way to do it will be to substrate the distance from the given radius, then divide it and translate the current point in that amount and getting the direction vector by (nearPointPosition - currentPointPosition).

Pseudocode:

for each carve in the carves
for each point in the carve
find near point
if nearPoint less than (cableRadius*2)
then
float tranf = ((cableRadius*2) - nearPointDistance)/2
vector dir = (nearPointPosition - currentPointPosition)
move point
else
keep current point
end loop
end loop


1) I am not sure how to move the point based on the above idea using the direction vector. (now I am moving in z axis)
2) It seems a bit slow when there are a lot of cables is there any way to make it faster based on what I have in the attached scene?
3) Any better other way to fix this?

thanks in advance for any help

I have wrote a code in python where I have a list of sentences and assign one sentence to each random point in an attribute. But it seems that in attribcreateSOP you cant use python when you are using string type, you cant use python even inside `` but you can use hscript. Am I missing something? Even when you RMB over the string parameter the “Change Language to…” is disabled.

P.S. is it possible to create a list in hscript?

what about the normals? when you instance with copySOP the geometry has the direction of the point's normal but in instance geometry all of them facing in the same direction. Is there any workaround on this?

Edit: my mistake, I had deleted the normals. It works fine.

insania
I don't think you can get the attributes from the points at the sop level of the instanced geo, only at the object level. So to get the color, you must use point() and instancepoint() on the shader. Take a look at the file.

digging little more to the forums I came in front of what you said, so I guess you are right but the workaround you are using in our attached scene works for me just fine. Thanks

P.S. I also found this from Peter Claes' blog and which is very interesting that combines copySOP with instancing in rendertime. http://www.peterclaes.be/blog/?p=34 [peterclaes.be]

cheers

I am using the Instance node in geometry level to render thousands of objects but I want to transfer the attributes like color from the points to the actual geometry as you can do in with copySOP. I have attached an example file. Thanks in advance for any help.

Joker386
Why don't you use TimeWrap SOP ?
It's so simple !

it works like a charm, sometimes in the answer is in your tab key. thanks

I would like to loop an expression-driven animation without using sim (pops or sopsolver), is that possible?

I have attached a file as example and I would like the sphere when reach the last point in the line, go back to the 0 point and repeat the same motion in a loop.

I know how to do that in pops but I am looking for one more procedural way without sim when changes can be made in real time.

It may sounds simple but is tricky for me.

cheers

I found the answer, you have to convert the relative path to an absolute path:

op:`opfullpath(“../cop2net/OUT”)`

and it works like a charm,

cheers

zdimaria
i dont know if this is supposed to be like this or not, but in my experience using op: has always needed to be an absolute path

Probably you are right. I have used in the past the op in a combination with opinputpath but now isnt that helpful. I was just wondering if you have an OTL which includes an COP, how can you access its output? You can't have an absolute path because it will brake the OTL.

It is probably stupid question but I can make it work and I cant find the answer in the forum. I have a COP network inside the SOPs and I want to read the final output from the compositor back to SOPs as image. Using opobj/geo/cop2net/OUT works! but the relative path op:../cop2net/OUT it doesn't! What am I missing?

cheers

http://www.youtube.com/watch?v=5qzU5KTi5b0&t=1m35s [youtube.com]

Hi, how can I approach this effect on the above link 1:35? It seems like they use fluids with high viscosity…. but I am thinking that maybe is possible in SOPs using vopsop and the pointcloud. I have attached a hip file where it 1 animated line and 3 vopsops where the first get the distance of every point in the line from its closest end point. The second vopsop computes the fake-gravity for the sticky fluid where the points that are far from the end points and close to the center of the line are affected more from the gravity and in similar way the third vopsop computes the thickness of the fluid along the line by editing the pscale attribute. Any suggestion for better and/or more efficient way to achieve this effect as realistic as possible?

hello,

I am back on the same topic. The director wanted to have real slow motion smoke in three shots. By using the time scale can be very tricky as it effects the simulation itself not just the time. By increasing the fps also effect the simulation. So I used a combination of time scale and Jeff's technice as you can see it in his post here. But I am getting a flickering and I cant understand why is that. I cant attach a file but I have attached few rendered frames. What can be this? The container is fixed and everything is as Jeff's setup for the retiming.

thanks a lot, I am gonna have a look and I will be back with more questions.
Just few more question related to volumes, whats the most important parameters (in rendering and shading) in order to have a high quality of fluid simulation and which renderer is the best to use PBR or Micro?
-How low can I go to the division size for the final simulation?

cheers