Thomas de Groot <tho### [at] degrootorg> wrote:
> On 16-7-2017 1:41, Sven Littkowski wrote:
> > I never actually used bump_maps before. Now I try to use one, but not
> > seeing any effect. Can someone assist me?
> >
> > The scene contains a stratosphere helium balloon, and the bump_map
> > should have created the typical balloon surface. However, I don't see
> > the surface changed. Before posting any images, I show you the scene
> > file. is there any error the way I do it?
> >
> > -------------------------------------------
>
> Same comments as Omniverse. I give you here an example from my
> BeenThereDoneThat scene, the moon in the sky:
>
> #declare MoonMap =
>    texture {
>      pigment {
>        image_map {
>          png "PlanetMaps/MoonMap.png" gamma 1.0
>          map_type 1
>          once
>          interpolate 2
>        }
>      }
>      normal {
>        bump_map {
>          png "PlanetMaps/MoonBump.png"
>          map_type 1
>          once
>          interpolate 2
>        }
>        bump_size 5.0
>      }
>      finish {
>        diffuse albedo 0.9
>      }
>    }
>
> That is all that is needed. The bump_size is even rather high but works
> best for this scene.
>
> Note that in order for the maps to be effective you need to add the
> map_type parameter which seems to be missing in your code. 1 is for a
> sphere. See docs for mor info on image_maps and bump_maps.
>
> --
> Thomas

Definitely onto something there Thomas. I was looking at it again because I
thought there was a reason for the default planar mapping, but I wondered if
that could be a mistake for this particular thing.
map_type 1 will wrap around the balloon shape spherically and not need
translate, rotate or scale.

But the main thing I was thinking about was to skip the image_map to get a
better look at what the bump_map is doing. So to try that, Sven, you might want
to look at it with only pigment { rgb 1 filter 0.5 } or similar. That way you
can see the normal alone.

I realized my attempt using my own image file masked the appearance somehow.
Probably something to do with the bump_map being like an illusion and not a real
surface deformation for the visible image to paint onto. So using the plain
pigment color it highlights the bump_map instead of masking it from view.
At least that's my thought on this.

Bob

Post a reply to this message