Hi everyone,

I just imported a model I created, UV mapped and textured in blender. Blender's FBX exporter is doing a great job since all of the geometry and material info is transfered to Houdini 1:1.

However, if I add a light, set up a camera and create a mantra render node I don't see any of these textures in the render (everything shows up textured in white, only materials without bitmaps show up with the colors assigned in blender).

Am I bound to replace all of the materials I created in blender and use only Houdini shaders? Or is there a “quick and dirty” way to get Houdini to read these materials and use their bitmaps?

many thanks for any ideas and guidance on this regard.
Regards,

Alvaro

ps. I encourage everyone to try blender's fbx exporter!

Most likely you'll have to recreate the shading and texturing with Houdini. Perhaps in the future, the FBX importer will be able to automate the process somewhat.

Cheers!
steven

I get textures here in 9.1 with FBX files I've imported. I suspect its the flavour of FBX. Are the shaders that the importer created finding the texture maps alright?

Don't expect the auto-shaders to do anything wonderous, though. They'll get you some of the way there as a start, but you'll need to do shading work to get anything close to final results. Also, keep in mind FBX import is in early release, and there's quite a bit of ‘flavouring’ going on out there in the FBX world.

Cheers,

J.C.

Thanks for the replies guys!

I get get the point. It's a shame bitmapped materials are not recognized automatically, it would make our lives so much easier, heheheh, let's hope they improve this in further releases. And let's hope FBX gets a bit more standardized so that other applications can follow a one-and-only format.

If I check the node structure of the file I imported, among all the geometry I see one called “materials” that contains the materials of my scene. When I double click on it I can see all of my materials as “surface shaders” but I got no idea how to modify them. I'll try to dig a bit more to see if I find any info on bitmapped materials.

Finally, then what you guys mean is that materials in Houdini are all shader-procedural based? a la Renderman? Or is there a chance to use bitmaps? I've found lots of good video tutorials to get started, but ironically material creation is one of the topics with the least info available.

Many thanks for the prompt answers.

Regards,

Alvaro

For me, anyway, importing FBX creates shaders that use texture maps without troubles. Be sure you're running the latest version of 9.1(we're using 9.1.229 here), FBX import has had some tweaks since initial release.

Also, as I mentioned, it can depend on the FBX file and the way the original package exported things.

Cheers,

J.C.

Thanks a lot JC.

As I wrote my reply, I played around with my scene and, man! all the materials are there! and each is pointing to the proper bitmap and everything, it's amazing how well-organized things are in these nodes! I had to update my previous post.

I'll download the latest version available since I'm still using 9.1.179

downloading now. Will report back in some minutes.

Regards,
Alvaro

ps. I see 9.1.238 available in the “daily builds” should I go for that one?

afecelis
ps. I see 9.1.238 available in the “daily builds” should I go for that one?

In general, you can check the change log at http://www.sidefx.com/index.php?option=com_journal&Itemid=213&page=index&journal=default [sidefx.com] to see what improvements have been made. In your case, it looks like many FBX improvements have been made from 9.1.179 to 9.1.238, so upgrading is probably a good idea.

I stand corrected. It's great to know the FBX importer has come a long way.

Cheers!
steven

Hi Alvaro,

afecelis
I'll download the latest version available since I'm still using 9.1.179
downloading now. Will report back in some minutes.

Let me know if textures still come in incorrectly with the new version. They should be fully supported by now.

afecelis
When I double click on it I can see all of my materials as “surface shaders” but I got no idea how to modify them.

There's two options to represent materials imported from FBX. One is to represent each surface as a special, monolithic FBX shader. You can control only the parameters this shader presents in the UI.

A second way is to import materials as VOP shader networks. In this case, each surface is represented as a collection of nodes, which you can dive into, add, remove, and otherwise modify any node you wish. If you're planning on creating more advanced shaders after importing the FBX file, I think it might be worth for you to try this mode first.

You can switch between the two different modes in the “Material Options” section of the FBX Import Options dialog box, next to the “Import Materials As” label.

Hope this helps.

wow! thanks a lot for all the support guys.

@Oleg: I tried opening the same hipnc file I was using and things are still the same. I'll try re-exporting from blender and importing from scratch in 9.1.238 to see how things go with the new material options.

I'll post some screenshots soon

Many thanks, apprentice HD is great!

regards,
Alvaro

ps. What's the difference between importing materials as fbx shader nodes or VOP networks?

afecelis
I tried opening the same hipnc file I was using and things still are the same.

This won't change anything because the FBX import code only runs when you import an FBX file; it does not run when you simply open an existing Houdini scene. You probably don't need to re-export from Blender, but you do need to re-import the FBX file into Houdini again (through the File->Import->FBX menu item).

Also, if you're going to re-export from Blender anyway, you might find it useful to export in ASCII mode - that way you can open the FBX file in any text editor and see whether it is structured properly.

If after re-importing the scene still comes in looking wrong, could you zip the fbx file and corresponding textures and attach them to your message? That way I can actually see what's going on.

Thanks Oleg. I did everything from scratch again.
1. Scene in blender:

2. Imported FBX in houdini HD:

3. Render after creating a ROP network and a Mantra inside of it:


I can't send you this file since it's a project I'm working on right now and I wanted to see Mantra's potential as renderer (right now for commercial stuff I use blender+yafray/kerkythea/indigo), but I can send you a similar one, with materials and everything. Let me get it ready for you

regards,

Alvaro

@Oleg:
Ok, here's an interior scene I created in blender as an exercise to try the new yafray render code out:

You can grab the FBX with the required bitmaps here:
http://files.wildspad.com/afecelis/houdini/files/interior.zip [files.wildspad.com]

FBX imported into Houdini:

Glass materials were recognized as such! (though they're blender shaders, not bitmapped materials).

Let me know if it helps and if you need anything else. Also let me know if you succeed in getting the materials to render. Little by little I'll keep pn asking stuff

regards,
ALvaro

afecelis
@Oleg:
Ok, here's an interior scene I created in blender as an exercise to try the new yafray render code out:

Wow, impressive scene.

I've imported the file you put a link to and played around with it a little. Here's the problem: materials which render wrong with Mantra have their diffuse coefficient set to 0, which effectively means you'll get no diffuse colour contribution (just the emissive and ambient in this case). However, the texture imported is set as a diffuse texture - so the renderer tries to apply it to the diffuse colour, which in the end gets multiplied by zero anyway.

I've also tried importing the same file into Maya, and it results in exactly the same grey colour instead of a texture.

You've got two possible fixes, both affecting the FBX shader node. One is to set the diffuse factor to something greater than 0 (however, I think in this case the texture appears to be mapped incorrectly); or to go to the tab “1” on the shader node and change the texture to be applied to the emissive channel instead of the diffuse one. In this case the plant leaves look correct, as far as I can tell.

Alternatively, it is entirely possible you could do some magic in Blender and avoid the whole issue altogether - but not being familiar with Blender, this is about as useful piece of an advice as I can give.

A quick update: actually, the UVs are correct. It's just that if you set the diffuse coefficient to 1, the emissive colour overpowers it. After playing around some more with the material, if you set emissive to 0, diffuse to 1, diffuse colour to something like (0.4, 0.4, 0.4), change the texture compositing type to “Add” and change the Alpha to 1.0, the material will look properly.

Note that for some reason, the exported FBX file also has the texture alpha value set to 5, even though it should be in the 0.0 - 1.0 range.

wow! that's great Oleg!
Thanks for looking into the scene! I'll try your recommendations out, and thanks for the kind comments. Architecture and 3d are my life and I love working on these fields. When I saw Houdini I fell in love with it, but I'm just beginning to learn it. So far I'll have to use the HD version for non-commercial stuff since even Escape is out of my economical reach by now But I'll start saving some bucks to see if I can get it in a nearby future.
Let me know if you need more scenes, perhaps I could provide you with some of my work so you guys can test my scenes out in Houdini

btw. Could you upload a render of your material-corrected scene?

best regards, and many thanks!

Alvaro
ps. Here's a quick render of the house in blender+yafray (still need the bkg sky to be composited and some postpro):

Hi,

That's a very nice render and I've attached a render of your file. I used a spotlight with Ambient Occlusion.

Cheers!
steven

wow! Steven! that looks great! Did you fix the materials as Oleg suggested? Or did they render right “out of the box” ?

Could you please share your hipnc file back? (upload it to some file-sharing/uploading service).

Thanks for replying!
regards,
Alvaro

Hi guys,
I tried fixing the materials following Oleg's suggestions but I must be doing something wrong.

When you say “set emmisive to zero” do you mean the emmision multiplier value? Same with diffuse color to 1, do you mean the diffuse multiplier?
I did it this way and then went to the #1 tab and chaged the other settings (composite do “add” and alpha value to “1”). Here's how I'm setting up my materials, one by one, but still some of them show up white (others are already showing the bitmap info properly ):



Or if any of you guys can upload a fixed version I'd really appreciate it, so I can check its materials

regards,
ALvaro.

ps. Now new questions arise; like how do you change the black background to something different? like a color, a gradient or a bitmap?

ohhhh! I think I'm getting it! ops: ops:
The settings Oleg suggests are just for the materials that are using a bitmap image, right? The other ones, which are simple blender materials, are easily replaceable by houdini shaders. I'm doing that right now! I'll post an image soon.

But then I shall remove the materials embedded in the FBX's “materials” node, prior to assigning the new shaders, right? Or will they be automatically removed when assigning the new materials?

Excuse me for so many questions, but I'm very excited, heheeh

regards,

Alvaro