Stumped By Particle Sampler Info Node

[rgkovach]

I'm using a Sprite emitter assigned a basic lambert shader with a single image (not using an image sequence).

The lambert shader has a custom attribute, a float with a min and max range of 0 to 1 (this attribute basically allows me to slide the alpha testing scale up and down to change the shape of the alpha channel).

Based on what I've read so far, I think what I am supposed to do is:

1. Add a userScalar1PP attribute to the particleShape.

2. Create a Ramp with the Input V set to Particle's Age by right-clicking in the field next to the userScalar1PP attribute.

3. Click on the Input Box next to my custom attribute and create a Particle Sampler Info Node and connect userScalar1PP to my attribute.

After doing this I would assume the particle's age is passed through the ramp into the userScalar1PP attribute. This value is then picked up by the Particle Sample Info Node and passed into my custom attribute, but this isn't happening.

Any help appreciated! Thanks.

[joojaa]

QUOTE(rgkovach @ 06/19/07, 05:36 PM) [snapback]268321[/snapback]
After doing this I would assume the particle's age is passed through the ramp into the userScalar1PP attribute. This value is then picked up by the Particle Sample Info Node and passed into my custom attribute, but this isn't happening.

right idea wrong scope. it only affects software rendering particle types in softwa rendering! And never instanced objects. So nothing is supposed to happen for the sprite object.

(ok now IF this would work what maya would end up doing is the images on fly so you can as easily use a sequence of say 40 images to do the same thing but faster instead)

Thing is hardware shading is completely separated form software, don't mix things up, hyper shade is for software shading, and only a subset of it is ever understandable for hardware rendering (in fact a very small subset, even then only e versy small fraction of that si sane in hardware rendering even if it will work)

[rgkovach]

so basically, if i decided to bypass sprites and instead use a polyPlane aim contrained to the camera and instanced that over a point-based particle (to create pseudo-sprites that I could render in software), I would have the same problem because of the instanced geometry?

The little shader network in Hypershade (which mimics the Threshold feature of Photoshop) does work in the viewport and renders in the software renderer, I'm looking for a way to control the Threshold attribute of my network over the particle's age. But it looks like I'll be writing a photoshop action to incrementally threshold my image and save out a frame...