Bump Map, Filter Blur, Bump Strength, Corona Bitmap

[Njen]

keeping always  0.01 will be wrong as it is good for close view renders - more details, but it will be completely wrong looking at distant view as it will looks too matte, also it will be longer to render and may produce noise

here similar discussion https://forum.corona-renderer.com/index.php?topic=22641.0

Never really had any visual/noticeable troubles using this method. I never do animations, so it wasn't a concern. Usually seems like the best approach was also using summed area versus pyramidal, but also to retain some blurring for bump. I rarely use the coronabitmap, so perhaps it's time to do some new testing.

This is not just a Corona thing, any renderer that doesn't properly account for distance filtering in the roughness channel will react with the same visual artifact.

I was present for the Bump to Roughness talk by Pixar this year at Siggraph, very informative.

[romullus]

I just checked the roadmap and filtering will be improved with V4, really good news! The next release will be freaking awesome!

In the roadmap only image filtering is mentioned, but not the bitmap filtering. That is slightly different thing, no?

[Fluss]

I just checked the roadmap and filtering will be improved with V4, really good news! The next release will be freaking awesome!

In the roadmap only image filtering is mentioned, but not the bitmap filtering. That is slightly different thing, no?

You're right, I read it too quickly...

[dj_buckley]

Well I ended up finding a balance between bump strength and filter blur.  As the bump was quite finely detailed, it did make a huge difference.  Setting it to 0.01 was massively increasing render time and affecting the light scatter too much almost giving a completely matte appearance.  I ended up testing a small patch of the render to get the blur right first so that the bump in render looked like the bump map itself (not too sharp etc), then I adjusted the strength to suit so the physical properties and how it interacted with the scene lighting behaved the same as the physical product I had in my hand, by testing under the same lighting conditions.  Admittedly, I've always just set everything to 0.01 until now and assumed I was getting the best possible appearance of the map and I won't be doing again