andreu.lucio

Oh! nice, I didn't know there was a vex one for that. I will use that for now. Thanks!

With the same idea of being able to play a bit more with the time in vops, it would be really cool to have an import animation channel with a time input in vops. Again you can do this in chops and or with expressions but it would add another way to control animation in vops. It's similar to using a ramp but with animation channels.

Yes, I know, I use chops too, and not sure if its posibble to do it efficiently but if it's possible I would use it all the time . I general I feel houdini it's already capable of doing "anything", so make things simpler to setup and faster to cook are best improvements can be made to houdini IMO.

A very simple but usefull one would be to add a time input to the import attribute vop "sort of like the chf() but per point" so we could get the value of an attribute in another frame. And or adding the $PT variable to the timeshift.

Hi, I totally agree with Dennis, A object level vops would be so nice improvement to replace expresions when working at object level. I understand there is many ways of aproching this. Thinking in the Vops SIMD architecture, one way could be done, is something like having objid as global parameters and transforms of those objects as output. And why not, any parameter that is in object level other than transforms, including spare parameters this way thing at SOP level could be triggered easily. I believe his would alow to create even complex behaviors with a combination of object level and SOP level. Regarding to what Dennis was asking for rigging, where you would want to 'import>doVopsMath>export' object level parameters as transfoms, this could be done with some kinf of import object transform (something analogous to the import attribute) and export object transform to output to the desired objects using regular expresions to determine which objects. All of this might be a crazy idea but it sounds potentially really cool to me. What you guys thinkabout this? Andreu

Nice render Sven. As Ryo said you can check the results of one of the cloud spheres in a volumeVop, in fact you can use the cvex shader changing the vex source parameter in the volumevop to shop and chose the cvex shader. I used antialased noise because it was just a test, but also because it has a litle advantage oposed to the fractalnoise because it can have a 4d input. This means you can animate a 4th value to have the noise evolving but staying in place. You can also use a multifractal and you will probrably get better results. And you can also use an antialased noise inside the multifractal so you can animate this 4th axis. The i3d workflow has the only benefit of been able to determine some kind of initial shape or even use a lowres simulation as a guide. But everything really depends in the kind of scene you are creating. For big cumulous clouds this technique can work quite well, but for a complete sky it may be more realistic to mix also some thiner clouds. Can be a hard work to make a complete realistic sky because of the complex nature and hetereogenity of the real clouds. Continuing with this technique you can pass volume attributes to the points from an initial volume were you scatter the points. So you can get more feeling of a group. Or you can also advect some particles trough a lowres fluid and you this particles and some attributes inerited from the fluids to instance this cloud spheres on they. The first part of the network before passing the P to the antialiased noise is for projecting P to a sphere to get a 2d noise as deformation for the sphere. The smooth vop does a smooth between two values, so the first value is the inner radio of the sphere and the second one is the outer. So its a combination of two values were the second one must be bigger than the first. So, adding the smooth parameter to the radio this smooth value will be the diference between the inner radio and the outer, giving a very hard edge if its 0 and a smoother edge while is increased. All the parameters you use in the cvex you can change per instance. Not sure if I explained well and hope it helps.

Here you have a very basic setup. basicVolumeProcedural01.hip

Have you correctly set the bounding box parameter in the volumeProcedural? You will also need a cvexshader exporting a density attribute for this setup to work. Have you done this 2 things?

There are many ways of mixing volume primitives, this is just and efficient method of instancing "noisy volume balls" on top of each point in the instance object. It doesn´t use any primitive because they are just balls displaced "pyroclastically", with the noise going outward the borders of the density. The points are created inside a volume and the volume balls are instanced on top of each point so the resulting shape matches the object. Maybe if you post an example of what you are trying to do maybe I can help you in a better way because I´m not sure about your question.

Hello Vincent, I´m not sure if I understood your question correctly but if point instancing proceduralVolumes is what you are looking for in the following file you can see an example. http://forums.odforce.net/index.php?app=core&module=attach&section=attach&attach_id=11713 And the post.

Hi Sven, They are both float fields with the density in it. One is used for the density itself and the other is converted to a vector with the gradient3d holding the outward direction. This vector field is used for displacing the volume in the right direction. When displacing geometry we use de normal for the displacement direction but when dealing with volumes there is no normal, that´s why the gradient is used.

Well, I think Hazoc´s first file does that, is just a mather using the new volume sops to do it with volumes from start and maybe a foreach to do it in a more recursive way. That´s the next thing I´m also trying to get, in fact it would be very powerfull to have a vop/vex function to calculate the gradient of a float field at render time without the need of any i3d or geometry cache. I think can be more complex than a regular function because the need of lookup for the neighbour voxels, and the vex functions they usually calculate each pixel-voxel separately. A custom function may be created by using arrays of the neighbour pixels but have not triyed yet and also I don´t know if would be to expensive to compute. So for now I want to try to do it in sops (the layer of the displacement sequentialy) with a medium resolution volume primitive and getting the fine detail at render time by using the resulting volumes as normals in the cvex procedural and maybe other primitives with the smoothnes or similar to have even more control in the highly detailed final result.

Thanks man! It´s true, I knew that option but I thougth it was not exactly the same, so I´ve been trying it with some scenes I did with greeble (with the sop solver) and it works exactly the same with a foreach inside a foreach. Just to be sure, they are exactly the same with the only diference of sop solver being time dependent, right? And so yes! Edward now I know it does satisfy all my needs. Thanks guys!

The same but with the noise projected to a sphere. PointInstancedCvex18.hip

Most of them, but really nice details can be created with very simple networks with recursion and the sop solver is great for that but I haven´t been able to do it without being time dependent. I would be great if the foreach itself had an option to act as recursive (I mean in each step plug the result to the next step as it does the sop solver). What I mis from processing while creating patterns in vex is the object oriented programming. This may be a crazy idea but whould object oriented vex be a very powerfull way of drawing procedural patterns? Or maybe a python shop? Just wondering... Would be very nice to be able to generate this kind of paterns at render time to use for diplaces, textures...