# Drawing per-vertex colored meshes and variable thickness lines

**URL:** <https://openrndr.discourse.group/t/drawing-per-vertex-colored-meshes-and-variable-thickness-lines/266>\
**Category:** OPENRNDR\
**Created:** [July 25, 2021, 8:45pm UTC](https://openrndr.discourse.group/t/drawing-per-vertex-colored-meshes-and-variable-thickness-lines/266 "2021-07-25T20:45:16Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![abe](https://yyz2.discourse-cdn.com/free1/user_avatar/openrndr.discourse.group/abe/32/700_2.png) [@abe](https://openrndr.discourse.group/u/abe)\
**Post date:** [July 25, 2021, 10:10pm UTC](https://openrndr.discourse.group/t/drawing-per-vertex-colored-meshes-and-variable-thickness-lines/266/2 "2021-07-25T22:10:54Z")

</div>

The code above was a preparation for this program, which converts an open animated shapeContour into a mesh (a triangle strip) with variable width and unique colors per vertex.

> **imports**
>
> ```kotlin
> import org.openrndr.application
> import org.openrndr.color.ColorRGBa
> import org.openrndr.draw.DrawPrimitive
> import org.openrndr.draw.shadeStyle
> import org.openrndr.draw.vertexBuffer
> import org.openrndr.draw.vertexFormat
> import org.openrndr.extensions.Screenshots
> import org.openrndr.extra.noise.Random
> import org.openrndr.math.Polar
> import org.openrndr.shape.ShapeContour
> 
> ```

```kotlin
fun main() = application {
    configure {
        width = 800
        height = 800
    }
    program {
        val geometry = vertexBuffer(vertexFormat {
            position(3)
            color(4)
        }, 100)

        extend(Screenshots())
        extend {
            drawer.clear(ColorRGBa.WHITE)
            drawer.shadeStyle = shadeStyle {
                fragmentTransform = "x_fill = va_color;"
            }
            val line = ShapeContour.fromPoints(List(geometry.vertexCount / 2) {
                val theta = it * 10.0 + seconds * 20
                val radius = 200.0 + 80 * Random.perlin(theta * 0.01, 1.0)
                Polar(theta, radius).cartesian + drawer.bounds.center
            }, false)
            
            val points = geometry.vertexCount / 2
            geometry.put {
                for (i in 0 until points) {
                    val pc = i / (points - 1.0)
                    val color = ColorRGBa.GRAY.mix(ColorRGBa.PINK, pc).toVector4()
                    val pos = line.position(pc)
                    val normal = line.normal(pc).normalized *
                            (40 + 20 * Random.perlin(pos * 0.01))
                    write((pos + normal).vector3(z = 0.0))
                    write(color)
                    write((pos - normal).vector3(z = 0.0))
                    write(color)
                }
            }
            drawer.vertexBuffer(geometry, DrawPrimitive.TRIANGLE_STRIP)
        }
    }
}

```

 ![WigglyLine-2021-07-26-00.08.02](https://global.discourse-cdn.com/free1/uploads/openrndr/original/1X/0c7162e1433d391e9d507d4f06f530b11b05a53b.png)

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