bump map problems

[3dkid]

Hello! Im getting strange results with simple material. I have a red, high reflective surface with just diffuse color. Lets say, i want to get something like bumpy paited metal.

So im getting this weird results. (You can see that high reflective dots on photos)

All i have is just a diffuse color with bump map (5mm)

Im tested it with free and last commercial version. I used just white light in environment slot and a hdri.

Im also tested this scene at corona 1.5, all the same, just diffuse and bump map, at 5 mm, and in corona it looks fine. (no dots) see last two photos for corona screenshots.

So i want to ask, can someone explain, what is this ? What im doing wrong ?

[3dkid]

also, with low bump, like 2 or 1 mm, i get good results, but if i want to use, for example 20mm, i have that spots again. But if i use 20mm bump at corona, everyting looks fine.

The problem is, i dont want to use corona, because i totaly in love with fstorm

[mitviz]

i have seen this myself a few times, would also love to know

[Karba]

also, with low bump, like 2 or 1 mm, i get good results, but if i want to use, for example 20mm, i have that spots again. But if i use 20mm bump at corona, everyting looks fine.

The problem is, i dont want to use corona, because i totaly in love with fstorm

Could you send me the scene? info@fstormrender.com

[3dkid]

I sent it, thank you.

[Karba]

Could you send me the scene? info@fstormrender.com

I checked the scene.
20 mm in FStorm is not the same as 20.0 in Corona.
FStorm uses metric bump power. Try to set something around 20000.0 in Corona, you will get strange result as well.

[ThreeMarks]

I am seeing a different bump map issue, but it appears to relate to its strength, particularly when there is a raking shadow across a rounded surface. There is a tendency for it to make the smooth surface appear faceted unless the bump is set incredibly low. I've run into this problem on a variety of materials, unfortunately. This can be worked around with other methods, like multiplying the bump map into the diffuse, but its an unfortunate error.

[Karba]

I am seeing a different bump map issue, but it appears to relate to its strength, particularly when there is a raking shadow across a rounded surface. There is a tendency for it to make the smooth surface appear faceted unless the bump is set incredibly low. I've run into this problem on a variety of materials, unfortunately. This can be worked around with other methods, like multiplying the bump map into the diffuse, but its an unfortunate error.

This is a common problem of most renders.

[ThreeMarks]

This is a common problem of most renders.

In 8 years of working with Vray professionally, I've never run into it. Too strong of a bump looks bad, but doesn't create these artifacts. At a tenth of an inch, it is understandable that there would be issues, but at 5 hundredths or even 1 hundredth?

[cdb]

this is the old "shadow terminator"

i ran into this again few days back in fs. when i switched to fstorm i tought i really bye byed those kind of problems but unfortunately it's not so.
it appears mainly on "very rounded geometry" such as chairs, pillows, wathever has a small and detiled bumps (like fabrics).

it's a gpu renderers bug, don't know the reasons and it's pretty annoying

however, you could try to add a falloff in the bump to smooth it out a bit, use a slightly blurred bitmap, multiply it on the diffuse channel a bit, also increasing the resolution of the model helps a but we know you can not turbosmooth to death of course.

i know these are workarounds but gpu renderings has his strength and weakness

[ThreeMarks]

cdb, thanks for the info. so much for pathtracing being physically accurate . i just took a quick pan around a scene i am putting together and it is everywhere. see attached. and all those bumps are set incredibly low. that is really frustrating, especially as it means that pretty much all soft furniture materials have to be made with work-arounds which sacrifice the visual quality of the material. Karba I really hope you can find a solution to this or that normal maps will fix the problem when they are implemented. its the first time since switching to fstorm that I have legitimately missed vray.

[mitviz]

cdb, thanks for the info. so much for pathtracing being physically accurate . i just took a quick pan around a scene i am putting together and it is everywhere. see attached. and all those bumps are set incredibly low. that is really frustrating, especially as it means that pretty much all soft furniture materials have to be made with work-arounds which sacrifice the visual quality of the material. Karba I really hope you can find a solution to this or that normal maps will fix the problem when they are implemented. its the first time since switching to fstorm that I have legitimately missed vray.

very very strange, been using fstorm for awhile now and have not seen this issue

[Karba]

cdb, thanks for the info. so much for pathtracing being physically accurate . i just took a quick pan around a scene i am putting together and it is everywhere. see attached. and all those bumps are set incredibly low. that is really frustrating, especially as it means that pretty much all soft furniture materials have to be made with work-arounds which sacrifice the visual quality of the material. Karba I really hope you can find a solution to this or that normal maps will fix the problem when they are implemented. its the first time since switching to fstorm that I have legitimately missed vray.

Could you please try this version?
https://fstormrender.com/forum/forum/...3ds-max-v1-1-3

[ThreeMarks]

Could you please try this version?
https://fstormrender.com/forum/forum/...3ds-max-v1-1-3

Andrey, you are the man. Honestly, this is awesome, absolutely blown away how quickly you handled this. Went through and looked at all of those materials in my scene, and all cleared up!! The only even remote vestige of the termination issue was in the striped chair, which cleared up with just an extra iteration of TurboSmooth, which honestly, it could have used anyway. I am attaching quick grabs again below. Thank you so much.

There's a new little bug that you can see in these images, regarding the environment visibility. I have the scene lit with an HDR in the environment slot. There is a large sphere with an emissive sphere encapsulating the scene for reflections and the background with the sky alpha'd out so that the HDR can be seen. Looking through the glass, the area that should be the hdr sky (the alpha'd part of the sphere) is rendering black. I am attaching an image of that as well (07.jpg).

Again, thanks so much. So happy you were able to take care of this and with such an incredibly short turn around.

[Karba]

There's a new little bug that you can see in these images, regarding the environment visibility. I have the scene lit with an HDR in the environment slot. There is a large sphere with an emissive sphere encapsulating the scene for reflections and the background with the sky alpha'd out so that the HDR can be seen. Looking through the glass, the area that should be the hdr sky (the alpha'd part of the sphere) is rendering black. I am attaching an image of that as well (07.jpg).

Fixed, will release a new version soon.