Renderman 22 Lookdev using masks
Using masks or ISOs as we sometimes called them is a common theme in VFX. We use them to alter textures or to apply effects limited to regions. In my case I exported two ISO maps from Mari, one containing text and another RGB mask. I was planning to apply a noise pattern as a micro bump and use the mask to limit the bump to a specific region. I also wanted the flexibility to make the text color editable in lookdev so we can have different colours on the text or swap the text entirely depending on future needs. The asset is going to be used in the new channel intro for Meshmen Studio.
ISO Tips For Texture Artists
A tip when dealing with ISO masks…before exporting them from your texture package is to overcrank them using the exposure and gamma sliders. You do this to check illegal values. It’s quite easy by mistake to choose a value near black or white. You really want to make sure your values are between zero and one in the ISO maps.
Another tip is to apply a clamp on your maps especially if you multiply or add values together on 16 bit channels. White looks white even if the value is 2 and if you use this mask in lookdev it can make life miserable for the lookdev artist.
Let’s take a look at how I used the masks in Renderman to create the lookdev for this asset.
As you can see using a few ISO masks can get you pretty far and combining this with the round cube workflow I used in the previous episode can apply even more breakup to the lookdev without even using any “Real” textures.
you can download Renderman non commercial and follow along….what are you waiting for?