Showing posts with label position. Show all posts
Showing posts with label position. Show all posts

Tuesday, 20 October 2026

plate camera projection in Karma or Solaris

How to do camera projections in Karma/Solaris.
 
Coordsys is the magic node. Below are the settings.. I want to project a plate image onto /grid using /camera1... so put their names in the boxes shown.
"tex" is an arbitrary name, we'll use it to access the camera space coordinates later, in the material. This is all that NDC stuff.
Just in case the images vanish from this site... Primitive Path should be your grid/projection geo, same again for the Primitives. Coordsys name should be something like "tex" and Target should be your camera path. Everything else can be left as default.


Material X Position is the node that gets you access to the NDC stuff..
We call on "tex" and the ":ndc" gets us to that space. Following that we get a vector, where we only need the X and Y...........which we separate out and combine to make a UV coordinate for the image sequence.


Assign your material to the projection object/grid and then switch to a Karma render view to see the result (VK does NOT display this correctly)!
If it doesn't work...check all your name paths!

Friday, 12 April 2019

solver sop and moving geometry

So, the Solver SOP doesn't behave as "I" expected with animated (ie. moving) points/geo.

You need to manually update the position if you want your geo to still move!
SOOOOOOOOOO. Inside the solver, copy the P (for position) attribute from Input 1 to Prev Frame...

Weird stuff. But hey.