# What is it **Mipmapping** is a texture optimization technique that creates and uses **multiple versions of a texture at decreasing resolutions**. ## Example: If your texture is 4096×4096 pixels, mipmapping generates: - Mip 0: 4096×4096 (full res) - Mip 1: 2048×2048 - Mip 2: 1024×1024 - Mip 3: 512×512 - … down to 1×1 These are called **mipmap levels**. # VIDEO - **ARTFX --> LOOK AT THIS VIDEO to know how to deal with MIPMAP :** https://kdrive.infomaniak.com/app/share/3120929/b9fe8632-ae06-4198-a862-6c8177dbf9e7 If you already cabled map and you want to replace to .rat or .tex easyly you can use HScript to do like a file repath in maya : [[../../NOTES/Houdini Repath Texture|Houdini Repath Texture ]] # .RAT .RAT is the file format of karma converted texture, it allow the render engine to generate the MIP level based on **screen space of the surface in camera** .RAT are always mipmapped - Theorically having a big texture don't matters when it is mipmapped as it will use only what the render engine need. Unfortunately this is theory only, and don't dispense you to use coherent Texel density. And it is not working on png or jpeg Note : loading a .rat file in mplay will only display the largest MIP level. # Optimising RAT Files - In houdini 20.5 : Right click on MTLX image node: Recipes / karma texture control - This controls how **finely Karma prefilters** the texture, which affects: - **Mip level selection** - **Texture blur vs sharpness** - **Performance** (especially at glancing angles) - ![[Pasted image 20250603001711.png|450]] - You can also do that with an EDIT LOP to assign on primitive directly - In houdini 20.0 : It is different, the easiest way is to play with **shading quality** in **render geometry settings.** - This parameter controls the quality of surface shading. Adjusting this parameter affects shading derivatives, which affects MIP map choices for example. **The highest the more expensive on render** - **Affect the dicing** : The effect of changing the shading quality is to increase or decrease the amount of shading by a factor of karma:object:dicingquality squared - so a shading quality of 2 will perform 4 times as much shading and a shading quality of 0.5 will perform 1/4 times as much shading.