Bitmap receding into the distance becomes blurry in 3ds Max / Vray

What to do when texture rendered in a steep angle becomes blurry in 3ds max? Do you have a problem with blurred bitmaps in vray? Especially when the bitmap is receding into the distance?

The problem is the filtering of that blurred bitmap. There is couple options you can play around with:

1. Change the "Blur" value

• Open Material editor
• Select the Bitmap that is causing the problem
• Under Filtering you can see Blur value 1,0 by default
• Lower the value and find best setting for you. (Usually around 0,1-0,8)
• Lowering Blur value too much might cause Moire patterns and slower rendering! So test your settings

2. Change filtering method to "Summed Area" or "None"

• The default method is "Pyramidal"
• Using Summed Area increases memory usage by 400%! This might not be the best options if you have a large bitmap
  
• Using None method might cause Moire patterns and texture crawl
  

3. Use Super sampling in scanline 3ds max

• Increase from default 1/4 to around 1/16

Try these methods and see which works best for you. Remember to test render and keep an eye on possible Moire patterns and lowered rendering times. Also remember to use uncompressed texture maps like Tiff, Targa, PSD. Using JPG will cause increased memory usage and lower quality.

When to use "Use interpolation" in V-ray material? What does it do?

Use "Use interpolation" option in Vray material to speed up rendering of glossy reflections or refractions/translucency. Interpolation option should be used ONLY in stills! Do not use it in animations, because it causes flickering.

It allows you to set Hsph subdivs and Interp samples separately from Global subdivs. This is usually done to smooth out a material that otherwise looks too grainy and to speed up rendering of material that is otherwise too slow.

Always test it before rendering the final, because with wrong settings it might look awful.

How to use it:

1. Material editor-->VrayMtl-->Reflection or Refraction-->Tick "Use interpolation"
2. Material editor-->VrayMtl-->Reflection or Refraction interpolation tab-->Tweak the settings and test (Compare with Global settings - Irradiance settings)