How do I bump my objects?

[reck]

I've created a simple cube object in blender and UV'd a brick texture onto it. I then created a bw version of the brick texture and loaded that into blender as a normal/bump map so the texture doesn't just look like a flat photo wrapped round the cube.

How to do I get this displacement affect in Terragen? I assumed I just loaded the bw image into the displacement image field within the default shader but it makes no difference, even if I alter the displacement multiplier.

Is there something wrong with my settings or maybe my bw displacement image wasn't created correctly?

Here are my settings and the result.

[Hetzen]

A few things to try.

Firstly, how big is the cube? According to your settings, you'll be displacing it by 2cm, which won't show up on a cube 100m.

Also, your displacment map, there doesn't seem to be a step in defference of grey between your grout and stone. I'd be tempted to have a look at the green channel in photoshop, to see if there is a better greyscale image to use.

[reck]

Hi Hetzen,

Is there a way to tell how big an object is in Terragen? When I imported it I scaled it up by a hundred so i've now reset the size back down to 1 and ramped up the multiplier setting. Before I scaled the object back down to 1 this setting did nothing but now i've reduced the size of the object i'm seeing some displacement. However it looks pretty bad, lots of spiky displacement instead of just the rocks being displaced. I guess this is a problem with the displacement map.

I don't have a lot of experience with creating displacement maps. All I did was the load the original colour image into GIMP and then desaturated it so I was left with a black and white image. Do you have any advice on the best way to create displacement maps in gimp to load into terragen? You mentioned something about the green channel?

[mr-miley]

reck

If you want to email me the colour image, my mate has CrazyBump, a most excellent bit of software for creating bumpmaps from colour photos etc. I'll run it through that and email it back

email:- miles at gintdev.co.uk (replace the spaces and "at" with a @)

Miles

[Henry Blewer]

Add a one meter sphere for reference. When using bump maps, think of the highest part of the surface as the whitest. I often reduce the number of colors (grayscale) to 8 or even 4. With less colors, it is easy to change the gray values. This allows for smoother transitions.

[FrankB]

simpler: just use the measure tool an see how large your object it

[Henry Blewer]

The reason I like to use a sphere is for scaling purposes. The measure tool only allows you to measure things, then it's gone. The sphere stays there until it's removed. A sphere also does not have flat sides, so the reference is available from any viewpoint.

[Dune]

You only have to remember that when the radius = 1, the ball is 2 meters high. 

[reck]

reck

If you want to email me the colour image, my mate has CrazyBump, a most excellent bit of software for creating bumpmaps from colour photos etc. I'll run it through that and email it back

email:- miles at gintdev.co.uk (replace the spaces and "at" with a @)

Miles

I appreciate the offer mr miley but I was doing this so I could learn how to create bump maps for use inside Terragen. I guess I need to know what procedure to follow within gimp to transform a colour image into a bumpmap.

It would be interesting to see what crazyBump could do though, but I don't want to waste your friends time when its not really for real project.

[mr-miley]

Reck

Ahh, sorry, didn't realise that it was part of a learning how to do it thing.... me doing it WOULD rather defeat the point of it slightly  I know that here was a plug in for gimp specifically for creating bump/displacement maps. I can't recall its name at this moment, and I'll need to be at my PC in work to find out. If I can find it I'll post its name / link here.

If i'm creating bump maps, I usually grey scale the image, then play around with the brightness and contrast, usually adjusting both upwards so you end up with an image that goes from black to a very light grey. Sometimes it helps to smooth/blur the image slightly to help remove spikes. I find it can be a bit of trial and error to get it just right, but worth it.

When you've got it sussed and are happy with what you can do, send me the colour image and i'll run it through my mates crazy bump so you can compare the 2. I find it gives great results, and it may give you some ideas about doing your own. It certainly gave me a few pointers. 

Miles