pixels : PIU : Tutorial Title

Introduction

By using the powerful functions of ShaderMaker we can create complex textures without resorting to texture maps. Making an apple using strictly procedural shaders is a good way to start. I chose to use a Fiji ( no Macintoshs were available ) apple as my inspiration.

PiXELS3D | studio | v3.6 and above
ShaderMakerPro 1.0

The Apple Modeling

First, we need an apple model. Launch Studio, and using the Shape>Spline, create a basic spline. Then Shape>Lathe the Spline. For the stem, if needed, create a Shape>Cylinder then use the Twist/Taper and then Reshape>Spline to shape it.

Now, lets export it as a File>Export>Export RIB File and save as Apple.RIB

Importing into SMP

We can easily import our Apple.RIB file into SMP to use as the primitive for troubleshooting the Shader. Click and hold on the Preview itself. When the popup-menu appears, simply select RIB file... then locate the file.

Apple Skin

We first should start taking steps into creating each part of the shader. Lets start with the easiest to control, the Bump. Our Bump will consist of two things, Turbulence and Granite nodes, to show the apple not being smooth plus it has dimples. Create a Granite and Turbulence node, now we will blend them together using a Math Function rather than a Blender Node. The Granite needs have tiny speckles ever so often plus be a B&W rather than a grey scale by controlling the Shades (1.42)+ Balance ( 0.74). Scaling, we should probably start at the basic 4.00 value until desired the higher the value, the larger the speckles. Now that we have both of our nodes

setup, let's link them into the Math Function and Add them together. We want the speckles to show thoroughly through the turbulence values, so set the Granite input lower than the Turbulence ( about 0.75 ). Now that we have this part done, link the Math Function into the Bump ( value about 9.0 ) and then preview, make any necessary changes so the dimples are not too discrete; but we don't want to bump the shader so high that it creates an unnatural skin. By also plugging in our Granite node into both the Ambience and Diffuse Values we can make the dimples darker than the rest of the skinned areas without resorting to the Bump.

Now we're ready to continue with the most difficult area of the shader - the colors. To start, we know that the apple is red with yellow tints near the core/stem. Create two User Defined nodes using these two colours. We know that we need to blend these two together with the yellow on the top and bottom of our shape creating 5 multiple Math Functions. Look at Math Functions 9, 12,14,22,92 using 12 to be the final step. Math Functions 14, 22, 92 is the top linear method while the 9 is the bottom. Link in your Y Current Point Local ( or Y Surface Angle, T Texture Coordinate ) into the 9 & 92 Math Functions to create the linear gradient, Math Functions 22 and 14 control the sharpness. Don't get too involved yet, lets set up the rest of the shader first.

For the coloring, we need to get the spotted colours of red over the base colour yellow. Create another Granite node, plus a Blender node for the Granite to plug into. Granite values, for here we also want majority B&W speckles but lots of them, control the Shades & Balance. Plug the red then yellow into the inputs of the Blender then the Granite into the Blending input. Next create another Blender node to blend both the red spotted colour and the yellow colour with the Math Functions 9,12,14,22,92. Link this new Blender into our Diffuse Colour and then render. You should notice that our Triple blending of colours form bottom to top. By now controlling the values of the Math Functions we can affect the blend of the yellow colour towards the middle of the Apples' skin.

Now we just have an ordinary apple skin, not accurate becuase we are still missing a cool effect. Apples not only have a speckled texture, but a streaky one as well. Going back to the Blender node of the red and yellow colours, lets create a streaky texture to replace the yellow colour. Create another Blender node. Plug in our yellow then make a dark red colour for the coloured inputs. Now create a Turbulence node and set the x & z values to 1.50, y to 13, to create a vertical turbulence. We want this Turbulence to have more contrast, so by creating another Math Function node and then Multipling the Turbulence by 3.00. we get a more B&W look. Link this Math Function into the Blender of the yellow and dark red. We should see a yellow with dark red vertical streaks in the Blender. If so, replace this into the yellow input or our red/yellow Blender ( Blender 20 in the image ). Render and we should have the basic procedural shader for the Apple's skin. To be continued...