Ideation, Creation & Everything In Between
In this stage of the tutorial I had to create a DOP Network in the object level I done this by using the tab menu and typing in DOP which brought up the DOP Network that I then placed on the network view as shown below. The next thing I had to do was rename the DOP Network I just created to SpraySim this is done in the same way I renamed the null nodes which is by double clicking on the text beside the node and typing whatever you want to call it. I then moved on to create a POP Object and a POP Solver within the SpraySim node level. In order to do this I had to use the tab menu and type in POP which displayed quite a few options I then navigated to POP Object and placed it on the network view and repeated this step with the POP Solver. I came across another issue with using different versions of Houdini, The lecturer in the video is using a much older version of Houdini and in the POP Solver node their is a setting called use external POP however I do not have this setting but took a wild guess and de selected the External Forces In this next stage I also encountered a problem with Houdini versions I needed to create a node called a source node however when I used the tab menu and typed in source I did not get the option for a source node so I took another wild guess and used what is called a POP Source node which turned out to be the right node. Here are the settings for the POP Source node as shown here I needed to select the navigate button at the end of the SOP option and direct my way through the operators to the particle_fluid and then down to the OUT_NewEitters and check the box export relative path box and then press accept. The options you can see above are in the source tab menu of POPSource1 I needed to navigate across to the birth tab menu in order to add an expression to the Const. Birth Rate option the expression went as follows : npoints(“../../../particle_fluid/OUT_NewEmitters”) This expression controls the way that the particles are emitted or born. Moving on an remaining on the SpraySim level of the network view I had to create a merge node this was done by using the tab menu and typing in merge and selecting merge and clicking on the network view to place it on the network view. Still in the SpraySim level in the network view I had to create a Gravity Force node in order to add gravity to my particles. This was done using the tab menu searching for gravity and placing the gravity force node onto the network view.
This video shows an example of what my waterfall now looks like with the force of gravity applied to it.
I then returned to the Popsolver1 settings in the Birth tab and changed to Life expectancy of my particles from 1000 to1. I also changed the Life variance to .25
From the object level I wen’t into the Landscape node and made the polycap1 node viewable by clicking on the box at the far right hand side this turned the box on this node blue and surrounded the node itself with a blue and purple circle. The blue circle indicates the node is viewable and the purple circle indicates that the node is renderable. Once I had selected the landscape node from the object node I pressed the static objects button in the Rigid bodies shelf. This made the water have a spray effect when colliding with the surface of the geometry. This works because I have applied the gravity force to my particles now. I had to then return to the SpraySim in the network view and delete the merge2 node as I had already created a merge1 node earlier in the process. To delete a node I simply click on the relevant node and press backspace. The images below show the network view with and without the merge2 node.
I also had to connect the staticsolver1 node to the merge1 node as shown in the most recent image of the network view in the slideshow below.