I have a pop network with a simple sprite and colour nodes. When I try to render my image all I get is grey planes - not with no transparency or shading. I looked at a previous post about how to change the colour - using an attribute SOP with Cd to Diff. However this removed the sprites from my render, even though they are in my viewport. Could some one tell me how to fix the sprite problem and how to get the transparency to render.

Cheers.

Perhaps you could post your file here?

there are a few video tutorials that show how to do this:

here : http://sidefx.vislab.usyd.edu.au/houdini_video/by_topic/effects/index.html [sidefx.vislab.usyd.edu.au]
the two in the Sprite Stamping section

at 3dbuzz : in the Video Tutorial section > Houdini VTM issue #4
12 Basic Sprite Rendering
13 Developing a Sprite Shader with VOPs

HTH

I have looked at these videos and I cannot see what I am doing wrong, perhaps I am just missing something. If someone could check my file just to see if I am doing something silly. Cheers.

http://people.pwf.cam.ac.uk/db410/sprite_problems.hipnc [people.pwf.cam.ac.uk]

Hmm, the short answer is that you should follow arctor's advice. Basically, you don't have a proper shader.

I have got the sprites to render as circles by following the 3DBuzz vid, but the particles will not render with the correct colour (from the Color Pop). pops are not covered in the vid. Any help with this? - it is displaying correctly in the viewport and the attribute sop trick from before will not work with sprites.

If you just want to render your coloured circles, I think you can just use a VEX Layered Surface SHOP without renaming Cd.

But I have the colour changing over time relative to the life of the particle.

Then have Cd change over time.