View Full Version : Line rendering challenge...

08-21-2007, 06:43 PM
I am posting this excellent link to see if any inspired node gurus out there can create an implementation of the some of the ideas discussed in this paper. The author at PIXAR stated that the render hit wasn't too bad and the look of Gusteau from Ratatouille is inspiring. Should be some way of using Unreal for surface IDs, edge tracing node, composite node with depth and normal weighting of some occlusion output, pull it all together with the Image node at the end and 'voila' at least in my fevered brain. DPont has created some very creative node solutions and CelShader seems to have a very good understanding of Unreal Line and CelShading. Take a look at this paper, collaborate, see what can be done. I am jealous of the Sketch&Toon and !Illustrate plugins and Lightwave seems to have all the makings.... Just wish I could stir the nodes...

09-21-2007, 05:36 PM
Bumping my own article reference, 'cause it is still interesting and I would like to see a response in this area of development.

09-21-2007, 07:17 PM
You could use a gradient set to incidence with a weight map multiplying it so weights of 1 are full line thickness and 0 no line. Unreal (the tool shader) also has nodal inputs for line thickness, so you can do quite a lot with that...

09-21-2007, 07:28 PM
So for example, here we have a weightmap piped into a multiply node (to scale the strength) then an add (to adjust the minimum line weight) and finally into the Pos input of a gradient node set to incidence. Very simple. There is a gradient running through the object getting stronger towards the bottom.

09-21-2007, 10:25 PM
I wonder if a light source could be used instead of a weight map.
So that an overhead light would result in a thinner line at the top and a thicker line at the bottom.

Or alternately could the distance of the outline to a null affect it's thickness?

09-24-2007, 10:12 AM
Dodgy, GregMalick, Thanks for the response. I am unwilling to just ask, "how'd you do dat," without making an effort. So, I made this simple scene and I have played with it six(6) different ways and "dem nodes defeat me." I have attached an image and a link to a simple test scene. The objects are just made for variety to try out the render ideas. I am familiar with UnReal, like some of the effects but would love to have a more complete manual and examples, my efforts always fall a bit short of expectations. If you have a test scene to take apart, great, if you can take a look and give suggestions, great, if you are too busy, I understand. I would welcome others to try these ideas and share examples. Max, Maya, Cinema, all have excellent tools, obviously the interest is there even Blender is getting new line rendering plugins.... Thanks all.
The simple test scene.

09-24-2007, 02:47 PM
Here's something you can do with unreal. I've coloured the objects to correspond to their weights, and plugged them into unreal's custom buffer (in the shader), which I then use in the pixel filter part of unreal. Very simple setup.

11-05-2007, 01:37 AM
Just a tip that's mostly OT and may be completely obsolete by now:

When I was using unreal a few years ago I found that I got much better results when I doubled the render resolution and then set the render multiplier to 50%. The final pixel dimensions were the same but the unreal plug-in worked better.

I was reminded of that seeing some of the lines cutting into solid areas on Dodgy's example.