Operator Tips

Wireframe Rendering Pattern

Reusable setup for wireframe geometry on black background:

python

# 1. Material
mat = root.create(wireframeMAT, 'wire_mat')
mat.par.colorr = 1.0; mat.par.colorg = 0.0; mat.par.colorb = 0.0
mat.par.linewidth = 3

# 2. Geometry COMP
geo = root.create(geometryCOMP, 'my_geo')
geo.par.rx.expr = 'absTime.seconds * 30'
geo.par.ry.expr = 'absTime.seconds * 45'
geo.par.material = mat.path  # NOTE: 'material' not 'mat'

# 3. Shape inside the geo
box = geo.create(boxSOP, 'cube')
box.par.sizex = 1.5; box.par.sizey = 1.5; box.par.sizez = 1.5

# 4. Camera
cam = root.create(cameraCOMP, 'cam1')
cam.par.tx = 0; cam.par.ty = 0; cam.par.tz = 4; cam.par.fov = 45

# 5. Render TOP
render = root.create(renderTOP, 'render1')
render.par.outputresolution = 'custom'
render.par.resolutionw = 1280; render.par.resolutionh = 720
render.par.bgcolorr = 0; render.par.bgcolorg = 0; render.par.bgcolorb = 0
render.par.camera = cam.path
render.par.geometry = geo.path

# 6. Output null
out = root.create(nullTOP, 'out1')
out.inputConnectors[0].connect(render.outputConnectors[0])

Key rules:

Class names: wireframeMAT not wireframeMat (all-caps suffix)
Geometry SOPs/POPs go INSIDE the geo comp
Material: geo.par.material not geo.par.mat
Render geometry: render.par.geometry = geo.path (string path)
wireframeMAT.par.wireframemode = 'topology' for clean wireframe (vs 'tesselated' for triangle edges)
Alternative: Use renderTOP.par.overridemat instead of per-geo material

Feedback TOP

Basic Structure

input (initial state) ──┐
                        ├──→ feedback_top ──→ processing ──→ null_out
                        │                                        ↑
                        └── par.top = 'null_out' ────────────────┘

Setup Pattern

python

# 1. Processing chain
glsl = root.create(glslTOP, 'sim')
null_out = root.create(nullTOP, 'null_out')
glsl.outputConnectors[0].connect(null_out.inputConnectors[0])

# 2. Feedback referencing null_out
feedback = root.create(feedbackTOP, 'feedback')
feedback.par.top = 'null_out'

# 3. Black initial state
const_init = root.create(constantTOP, 'const_init')
const_init.par.colorr = 0; const_init.par.colorg = 0; const_init.par.colorb = 0

# 4. Wire: initial → feedback, feedback → processing
feedback.inputConnectors[0].connect(const_init)
glsl.inputConnectors[0].connect(feedback)

# 5. Reset to apply initial state
feedback.par.resetpulse.pulse()

Common Errors

Error	Cause	Solution
"Not enough sources specified"	No input connected	Connect initial state TOP
Unexpected initial pattern	Wrong initial state	Use Constant TOP (black)

Tips

Use float format for simulations: glsl.par.format = 'rgba32float'
Reset after setup: feedback.par.resetpulse.pulse()
Match resolutions — feedback, processing, and initial state must match

Soft boundary prevents edge artifacts:

glsl

float edge = 3.0 * texel.x;
float bx = smoothstep(0.0, edge, uv.x) * smoothstep(0.0, edge, 1.0 - uv.x);
float by = smoothstep(0.0, edge, uv.y) * smoothstep(0.0, edge, 1.0 - uv.y);
value *= bx * by;

Use Cases

Wave Simulation — R=height, G=velocity, black initial state
Cellular Automata — white=alive, black=dead, random noise initial state
Trail / Motion Blur — blend current frame with feedback, black initial