Applying IRay Shaders to ZBrush Sculpted Objects

Fragg1960

I've been doing a fair amout of hi-res sculpts in ZBrush (original scultps) to teach myself to use the program better and build myself a prop library for personal use.  I want to import those objs into Studio and use them as props.  I can bring the OBJs into Studio and pose them just fine, but when I try to apply a shader to the object (for example--one of the Filthy Dirty IRay shaders) the object just turns a solid color and it does not display the texture information from the shader.  If I create a primitive (a cube for example) within Studio and apply the same IRay shader, I get the shader's full effect and it looks fine.  Not sure why it works in one instance but not the other. Can anyone shed some light on this or have any ideas why it could happen? 

Richard Haseltine

Are you UV mapping the items in ZBrush?

Fragg1960

No. I'm new at this so I guess that would be the problem?  I mean my sculpted details and all come over fine into Studio, so I guess the UV maps provide the shape information that the shaders need to apply to wrap around the surface mesh.  Got it.

mjc1016

UV maps match pixels to vertices/faces.  They tell where a certain color/image goes on the mesh...

Fragg1960

Yeah, now getting the UVs to work is another matter.  After watching videos on using ZBrush UV Master and following along to create the UV maps (which was fairly easy) and exporting them (all worked well), still can't get my model to look any better in Studio.  How do I tell Studio to use the UV I created?  When I bring the obj into Studio and go to the surfaces tab and scroll down to UV set, all it says is "Default UV."  Should I be able to tell it where my UV is?  Do I load the UV in the ambient color channel as a map--how does that work?

mjc1016

After you created the UV in Zbrush...did your export the obj?

Once UVs are created then that coordinate info is stored in obj file, so a mapped item doesn't need anything else done,  that will be the 'default' UV that Studio uses.  But if you haven't resaved/exported the obj, then Studio is still using the unwrapped/mapped version.

Fragg1960

So the UV info is embedded into the OBJ out of ZBrush?  Ah, so even if I had already sculpted the object and I just wanted to generate the UV, I still have to re-export the object when I create the UV so the UV info is embedded.  Did not know that step was necessary (the fact that the OBJ export was necessary was not mentioned in any of the tutorials I watched).  That is a pretty important step.  Thanks.

Fragg1960

Okay getting there.  I may have done something wrong, but once I exported the object, it does pick up the UV in Studio.  However, when I apply a texture to the OBJ, some parts of the model look black while others have the texture.  Do I have to invert textures or something weird like that to get them to fit the object or did I mess up my UV when I created it (it's possible).  I'm sort of there but not yet--obviously did something wrong because it does not appear to be mapped correctly.

Jimbow

Does the model have more than one surface material, and do all surface materials have the same textures applied?

Fragg1960

Did a horizontal flip on the texture and now all is right with the world.  That is something else handy to know--you have to flip the texture to make it fit.

mjc1016

Fragg1960 said:

Did a horizontal flip on the texture and now all is right with the world.  That is something else handy to know--you have to flip the texture to make it fit.

You could also have the import settings into Studio wrong...like a flipped axis.  Or the normals could be pointing the wrong way...

Fragg1960

Thanks--all working.  Took a lot of notes--now I know how to do it.  Have to check on the import settings for textures, but it's no biggie.  If they come in wrong I just flip them until they fit.  Now all Studio shaders apply correctly.  Thanks all for your input---it was a good learning experience.

Richard Haseltine

Yes, maps exported from ZBrush have to be v-flipped - there is an option to do that in the map export settings inside ZBrush. The same is true when importing a map for use in ZBrush.

Thor

I just use GoZ instead of all the exporting/importing business.

Create new scene in DS

Add a figure (Gen 3, usually)

Go to File > Send to ZBrush

In Zbrush, append your object as a subtool

Do your texturing/UVmapping

With the object subtool selected, click the GoZ button

ZBrush will send the object back to Studio, and prompt you to add the object.

In Studio, I usually apply the DAZ !Iray Uber base shader to the new object, then load the texture that I created/edited in ZBrush for the base/diffuse in surfaces.

 

 

 

 

 

 

Fragg1960

Thor said:

I just use GoZ instead of all the exporting/importing business.

Create new scene in DS

Add a figure (Gen 3, usually)

Go to File > Send to ZBrush

In Zbrush, append your object as a subtool

Do your texturing/UVmapping

With the object subtool selected, click the GoZ button

ZBrush will send the object back to Studio, and prompt you to add the object.

In Studio, I usually apply the DAZ !Iray Uber base shader to the new object, then load the texture that I created/edited in ZBrush for the base/diffuse in surfaces.

I use the GoZ bridge quite a bit.  But since I'm doing a lot of original prop sculpts in ZBrush, I had to learn how to do the UVs for my original stuff so that I could use IRay assets in Studio.  And since Studio automatically downgrades the HD of anything coming through the Bridge and I want to retain my HD sculpts, that just left one option open.