I am currently trying to create the tread on a car tyre and wondering where the bump map channel is located ???

I have tried using the displacement slot but the edges turn jagged because of the lack of polygons, i think ?

In 3ds max dragging the same texture into the bump map channel would create displacement, even when using low polygon and wondering how to do this in houdini????

Thanks

If you use a material with displacement, there should be an option called “True Displacement”. If you uncheck that you get bump. If it isn't there you can add it either in the material, or the renderer via the render parameters.

So I found this thread because I do not understand how to do bumbmapping. Well, actually I know how it works but I'm not quite sure I get the houdini approach on it. Since bumpmapping is such a common task I assume there is an easier way then coding the effecta of a bump oneself in an illuminance loop - Ii hope there is!?

is there?

reread Soothsayer's post

if you use displacement shader in material
just add Properties SHOP and add True Displacement Rendering Parameter (vm_truedisplace) from gear menu then uncheck it

many Displacement materials from Palette have this setup already done so for them just uncheck True Displacement to get bumpmap

you can even alter normals directly in surface shader and use them for shading to get bumpmap effect and avoid displacement shader

Turning a bump into a normal map is nothing that I'd just do in a quick VEX network (unless there is a gradient-operator somewhere), so I don't know how affecting the normal could be of any help in regard to bumpmapping. But thanks for the hint on fake displacement - I didn't understand that I'd have to add the parameter on my displacement shader.

all that bumpmap does is affecting the normal

to surface shader approach:
you can use Displace Along Normal VOP in Surface SHOP to get altered normals
just plug your bump texture to Amount input and use Scale input to change bumpmap intensity
then you can plug that altered normal to Lighting Model VOP or Lambert or phong or whatever

ah cool, i didnt know that there is a displacement vop for surfaceshaders. that sounds like bumpmapping. i thought by refering to the normals you were refering to normal mapping- thanks then

ironically enough there is Bumpmap VOP in surface context which does this

i didnt find that. I looked into the docs for a bump and I found http://localhost:48626/nodes/vop/bumpmap [localhost] to be the only possibility. i pressed tab in surface context and there was nothing starting with “bump” so i gave up. what is the name of the op that you are refering to?

it's called Bump Map
it's located in Displace section of Surface SHOP TAB menu (in Displace SHOP too)

you should find it however with just typing “bump” in TAB menu
not sure why you can't find it

Erm, all the time I was looking in the VOP RSL surface shop, sorry - i should read better