Digital Process – Report (500 – 750 words) – Orange Bump Tutorial – Lisa Gane
Above is an image of the final product. Color and final attempt are also up to the artists discretion.
Using a NURB based model of an orange we are going to create a procedural texture network using stacked bump maps to created a realistic look using Autodesks Maya. Below shows we will be using 5 stacked bump maps using noise to achieve this result, I find subtle changes are best.
Before I start any bump maps I like to put the color together. Since this tutorial isn’t about color I will skim quickly over this. After applying a PhongE shader to the orange, map a ramp into its color attribute. Change the ramps direction to the U direction and map a fractal into each of its color nodes.
Your orange should now look like this. In each fractal change attributes to suit and change the textures color offset and gain to colors that suit an orange and appeal to your taste.
Here is my color choices for the orange. Please note ray tracing is turned on.
Now it is time to start our bump network. If you feel using a different texture other than noise you are free to do so, however I found my best result was with only using noise.
Map a noise 2D texture into the bump node of the PhongE that is applied to the orange. Your first result will look something like this.
Set the bump map depth to 0.100. Within the noise attributes, turn on invert. Below are the setting I used in the attributes to build up my first bump map. This will become the basis of the next 4.
Note that the noises indents are still quiet large. The first 3 bump maps are used to create the skins texture, while the last 2 are used to create the orange’s pores.
Within the hypershade, select and duplicate this bump map. To stack the bump maps, right click the output (out normal) of the duplicated network and left click into the input of the previously created bump map (other). By selecting other, the option box will show up. Here we will choose the out normal on the left hand side and the out camera on the right.
Now the bump maps are stacked. We will use this same process to connect the remaining 4 bump maps. The new bump map will have these attributes in the noise.
For the third bump map, set the bump depth to 0.090, and the following attributes.
Your orange should now look something like this.
For the last two maps we will change the placed 2D texture node to repeat on the u and v axis to 13.000. This will bring the noise texture closer together for the pores. The bump depth will now be changed to 0.060 since these bump maps are stacking each new bump map needs to be softer otherwise the result will be too harsh.
After entering these new attributes your orange will look like this.
Some people would stop here, however I want to add one more bump to make some of the pores a little deeper than the others.
For the final bump map, the bump depth is set to 0.030 and the attributes are as follows.
Your final render should look something like this.
Congratulations on finishing the tutorial, finer tweaks can be made at this point to gain the desired result.