Chaos Corona Forum
Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: labotory on 2018-11-29, 13:16:02
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Hello
Someone can explain me how work Blur in Bitmap parameter (Filtering section) ?
By défault the value is 1 but I do not understand what changes if I set this value to 0.5 or 0.001.
Thank you guys
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3ds Max has great help system, you can find your answer there. In short, blur controls how much bitmap will be blurred depending on its distance from camera. If you want blur that would work like in photoshop, then you need blur offset.
http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-8AE3643F-BDB4-498B-B220-92646FC8A562#GUID-8AE3643F-BDB4-498B-B220-92646FC8A562__GUID-8AE3643F-BDB4-498B-B220-92646FC8A562
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3ds Max has great help system, you can find your answer there. In short, blur controls how much bitmap will be blurred depending on its distance from camera. If you want blur that would work like in photoshop, then you need blur offset.
http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-8AE3643F-BDB4-498B-B220-92646FC8A562#GUID-8AE3643F-BDB4-498B-B220-92646FC8A562__GUID-8AE3643F-BDB4-498B-B220-92646FC8A562
Thank you for your help.
That mean if i dont want blur it stay with 1 ?
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No, default value adds quite significant blur. If you want minimum blur, then set it to 0.01
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No, default value adds quite significant blur. If you want minimum blur, then set it to 0.01
Get it !
Thank you very much !
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In my experience, reducing the blur value to minimum values is expecially very useful and needed for objects like floors or roads that are usually seen at an angle almost parallel to the view. In those cases the texture would lose most of its detail with the default 1 value.
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The blur/filtering of bitmap always annoyed me in 3dsMax. The default type/value do blur textures needlessly, but if you make it into 0.01, you will soon find out Corona will struggle with it, esp. if it's bump/normal slot. It's very easy to trigger visual artifacts this way (to a point where it for example completely erases specular layer !!), particularly with high-res textures with lot of micro-detail.
Imho Corona Bitmap should introduce higher quality algorithm for filtering, like the Elliptical in Vray.
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In my experience, reducing the blur value to minimum values is expecially very useful and needed for objects like floors or roads that are usually seen at an angle almost parallel to the view. In those cases the texture would lose most of its detail with the default 1 value.
Except that blurring has nothing to do with mesh angle to the camera, but only with distance. If your floor would be perpendicular to the camera, it would loose as much detail as the floor that is parallel, given the same distance to the camera. See attached examples, notice how texture gets blurred more with distance from camera and how that equally affects both parallel and perpendicular planes.
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Thank you for the explanation and example Romullus; good to know!
I Always thought that the inclination of the object played a role in the rendering of the texture because, like I also see in your example, the details of parallel objects look more crisp with low blur values while in facing objects the difference is less noticeable…
Thank you!
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I think you just see what you want to see :] In my opinion both surfaces are affected equally.
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I agree, they are affected equally. What I meant is only that I find a low blur value particularly useful with objects more parallel to che view, as it helps keeping the details of the texture sharper.
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romullus inconclusive demonstration =) but yes in some case it's more noticeable, especially at small detail like small bump at matte plastic for example, blur 1 just erase details with distance
(http://imagizer.imageshack.com/img923/8436/AQlXJy.jpg)
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Neither looks correct to me though :- ( Blur1 just forgets the texture is there...and 0.01 completely overtakes Fresnel. Corona would benefit from both 1) Microgeometry sampling (paper in other thread, apparently already in F-Storm) 2) Much better filtering alternative --> elliptical (but does anyone remember when Bertrand used to use VrayHDRi for bump map because it had superior filtering already by default ?)
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Neither looks correct to me though :- (
Agree, but blur 1 still looks much better to me. But the worst part is, that blurring is highly dependant on rendering resolution and camera position, so there's no single "true" value and you constantly need to fiddle with that. Such thing should be automatic. Nvidia could empower its AI algorithms to help us here :]
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Neither looks correct to me though :- (
Agree, but blur 1 still looks much better to me. But the worst part is, that blurring is highly dependant on rendering resolution and camera position, so there's no single "true" value and you constantly need to fiddle with that. Such thing should be automatic. Nvidia could empower its AI algorithms to help us here :]
Agree 1000perc. This is reason why I don't touch it for meanwhile. 1.0 blur, default filter (I never noticed summed area to be improvement, just memory hog), erases detail, but at least it doesn't produce artifacts. Everything else works only for particular situation, and I am not gonna change filter for different camera & resolutions, that's total nonsense.
I am actually surprised Autodesk never did any improvement on native bitmap reader.
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A value that usually works for me without having to modify it depending on render resolution and view angle is 0,1 or 0,2
Not too crisp but well defined...
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My solution for the past 10 years or so was to always deactivate mip mapping or blurring, render at a double resolution and then resize back down with a good algorithm. This method solves the flickering and noise added by too high frequencies added by lowering the texture blur and also improves lots of things in the process, but you're paying with a higher render time. This method also especially improves distant objects and textures and problematic aliasing areas.