materials for RBD fractured object?

[weining]

Hi guys,

I have a problem about applying multiple materials to a RBD fractured object, I wanna this stone has a textured material like old aged outside, but inside with another material which looks a bit fresh. So it could make sense when it's smashed.

Here is my set up, I bet something wrong there...

I assign a Houdini granite mat to the whole 'stone' at OBJ level, which get some bumps and noises result for the both outside and inside shaders.

Then dive into the GEO level ,assign a VEX layered/displace material and uvunwrap it to make a different looking surface.

The problem is, when I render out the image sequences, the inside of the 'stone' is always floating or flashing, seems the noise of the granite mat stays where it was. Doesn't follow the movement of the RBD 'stone'.

I can't sort it out, I tried to just apply the granite mat to the 'stone', but its still the same problem, thanks for help

[rdg]

The problem is, when I render out the image sequences, the inside of the 'stone' is always floating or flashing, seems the noise of the granite mat stays where it was. Doesn't follow the movement of the RBD 'stone'.

Sounds like you need to assign a rest position to your object. Use the restSOP.

Hope this helps.

Georg

[weining]

Get it ! Thank you Georg!!

So I did like this:

OBJ level ---material (noise displacement for inside)

GEO level---sphere, material (tex for outside), UV, cookies, groups, merge,dopnet, then rest. At restSOP, first input from RBD fractured dopnet, second input from merge.

Finally, the noise stays where it was.

But how can I do if I wanna UV inside as well?

Cheers!

stone.hipnc

[zasid]

Hi ,

I have fixed the problem attached is the hip file.I had similar problem in my last term project.I hope this is wat you wanted .Having two textures on a same geometry and they both shud be non floating .I hope it helps.

stone_fixed.hipnc

[weining]

Hi Zasid,

Thank you for the suggestion, I have watched you hip file, the network looks very clear and neat.

I have noticed you used two group SOPs in order to apply different materials to them, The problem for me is I have got over 30 pieces of rocks which all are RBD fractured from a single geometry, I can't select primatives by hand...

[zasid]

Hi ,

Use this technique before sending them to dops.first select the top faces decalare them as groups and then select the bottom faces and declare them as another group and apply ur material.once u send them dops as fractures RBD there is a masking option their put the names of ur fractured chunks groups lets say ur groups are like chunks 01 chunk02 chuck 03...and so one so just put chunk* and it will take only broken groups with proper material applied on them.and will ignore ur 2 top material groups.HTH.

[weining]

Hi Zasid,

Thanks for your reply. Sorry I am a little confused about groups. I still don't know how to select the primatives/faces inside of the geometry, not top and bottom faces. The two materials would be one assigned to the whole surface of the rock, rest materal will be assgined to the rock inside.

Cheers!

[zasid]

Hi,

Please goto the top viewport and select from their.but this technique would work only on planer surfaces such as wall.Can u post or Crack Geometry so that we can have a look.Thanks.

[weining]

Hi Zasid,

Here is the hipnc file with a simple Digital Asset otl for hand cutting geometry by myself, if turns error plz install it. Many thanks. I temporarily delete the material nodes for a smaller size, but u can see material SHOPs inside of the rock.

Cheers

rock.zip

Edited August 6, 2008 by weining

[zasid]

Hi ,

I have made and example file to fix the problem please have a look .I hope this will solve ur problem.you are not using the group option in ur cookie cutter which is very imp to exploit if you want different texture on onto ur geometry.I hth.

Rock_texture_fix.hipnc

[weining]

Hi Zasid,

Cool, I know where I did wrong now. :thumbsup: thank you for your kind help!

Edited August 6, 2008 by weining