Martin Widö

With the caveat Ive not worked in 20.5 and I know there is a "see through" function to the sop modify LOP.


We import / export everything as usd via solaris. If we are to do something with the geo, we are LOP importing it to /obj and when done, SOP importing it to solaris.
The reson we are building/simulating in /obj(build) context is, we like having all simulation components in one geo container. This way I can have them influencing each other without importing/exporting every components throug LOPs and different networks.

We are also using freelancing artists and everyone knows SOPs, but few know LOPs. We want them to get into sops as fast as possible and stay there as long as possible, purely use solaris with scripted i/o for lookdev and publishing to other departments.


If you do smaller stuff I really dont think it matters. The sop create and sop modify are wrappers with build networks inside them and will in many cases convert the geo anyway.

In simple terms...
DOPs work differently then the SOP context.

Dops is collecting data its then trying to solve in each timestep using a... solver.
If you look in your geometry spreadsheet when in DOPS. You will see your objects and the assigned data.

kodra
The ground plane object is not connected to RBD Solver. How does RBD Solver know its existence? Why does RBD Solver know its a collider?

If you look at the merge node. Its set to create a collision relationship between the connected objects.

kodra
And even more confusingly, they all eventually connect to a Gravity DOP. Then why the RBD Object is affected by gravity, but the ground plane isn't?

The ground plane doesnt have a solver attached to it. You will see this if you expand the objects in the geometry spreadsheet.
Each type of DOP object also got different types of data attached to it by default, wich you can see if you dive inte the rbd or ground plane nodes. You cant just plug any solver to any object, since you most probably will be missing data for the solver to work on..

So much is simplified around DOPs now adays and some of the hacks you had to do to minipulate these data tree to get what you wanted was crazy.
I think there are a few really old threads + hips from jeff wagner with examples and explanations floating around here or on odforce if you are interested.

Here Im fetching Cd. But you might as well get the uv atribute from the hit and apply the color map to the scattered point.

did a example using the ray node to send several jittered rays aswell.

There are examples floating around with "complete" pathtracers done in SOPs.