Controlling procedural bump value / depth - Baking Bump

[Aunty Betty]

I'm confused by how to control bump depth in Carrara using a procedural function.

How is the depth value / amount of bump applied controlled?

danilo says this:
in order to obtain better bump with Carrara (4/5) you need:
1 - convert your bump map into a grey scale image
2 - eventually normalize the grey scale bump map having the darkest color equal to black and the lighest color equal to white

How for example do you convert a procedural bump map into a greyscale image?
Perhaps Danilo is talking about an image map bump.

I must admit to finding the shader tree in Carrara more confusing in layout and functionality than other 3D apps I use. The penny still hasn't quite dropped yet with many of it's features.

Help me be a better person.

Yours

Aunty Betty

[AWBenson]

You don't have to use greyscale for the bump channel. It will however only recognize the greyscale content. For example, you have a bright yellow and use that in the bump channel; you will get the same effect as a light grey color.

Anyway, "How for example do you convert a procedural bump map into a greyscale image?" can be done through a plugin called Baker. It's not needed for using procedural textures in the bump channel.


What he is talking about is having a range from black to white on a bitmap image placed in the bump channel. This isn't necessary but will give better results as there are more shading steps involved between bump height/amptitude (Carrara calls it amptitude).

If you want to control the amptitude of a bump and through C5, click on the top level channel. You've get a summary of all the channels in the right column. If you notice in the bump channel, you will now have access to the amptitude setting which isn't available if you click on the bump channel directly.

[Aunty Betty]

AW, many thanks indeed.

Ah, click on the top level channel and there it is. I was trying to search for this function within the bump channel itself.

Thanks for taking the time to point out such things as the Baker plugin - looks useful.

Best Regards

[AWBenson]

If you plan to use Baker, you MUST unwrap your objects otherwise your results will be very unpredictable (and usually un-usable). Might I suggest the tutorials on my website for this task? O

On the postive side, if you do use Baker. It will speed up the final render time considerably. I does take time to render the procedurals to a texture (image) map but that is eclipsed by the amount of time you save by re-rendering and animation renders.

[mykyl1966]

hmmm. You got me thinking. I wonder how baker will be for baking out procedurals with a AUV tiles map. Going to test and find out.

Cheers

Mike R

[mykyl1966]

Well it bakes it but when you use that texture on the model the model is invisible. You cant get it to show up at all. The shadow is showing in the texture room but no model wierd.

if you change it to colour = an actual colour it works again but as soon as you use that texture created it goes invisible.

Cheers

Mike R


Cheers

Mike R

[AWBenson]

Have you tried looking on the Baker created map in PhotoShop or another bitmap editor?

This should tell you if there is a problem with the file.

If not, then this is weird because Baker doesn't mess with the UV settings.

[mykyl1966]

It must have been a glitch. It does work. I started again but this time used a bmp file as the output. Only of use for render speed. No use for tweaking the map. ;) Leaves tiny little seams between the tiles though as well.

Cheers

Mike R

[Aunty Betty]

mykyl, be interested to hear if you manage to solve this.

Aurick at ZBrush central I'm sure would shed some light on this.