I am running 9.5 on Vista64.

Having all forms forms of rendering problems. I am not certain the whole thing is working. My experience is mainly with Maya Mental Ray, so working with Mantra is somewhat painfull.

Mantra. Man I just do not understand how to work with it.
Added Light Template, assigned it a VEX Global Illumination shader. In that SHOP, assigned it a 32bit floating point HDR image. In a scene of a box , with inverted normals , and sphere, the scene renders black. Mantra options is set to Physically Correct. If set to Global Photon Map Generation, the scene fails to render.

What is the Manta version of IBL with Final Gathering? Where is the HDR image is added?

Help files. don't seem to work. Whenever Help is invoked, the empty help window seats there with message “Waiting for Localhost”.

Another problem is constant expression crashes.
Lets say I have this expression in a channell
fit(rand($PT),0,1,.1,.5) controlling the radius of a stamp param in CopySOP. If I were to change .1 to another number, Houdini crashes. Even if it is set to Manual update.

Maybe I should just stick to Maya when it comes to rendering. Mantra is too frustrating.

Vent!

David -
you can get to the help files here:
http://www.sidefx.com/docs/houdini9.5/ [sidefx.com]

like this
http://www.sidefx.com/docs/houdini9.5/light/ambientocclusion [sidefx.com]

not sure what's up with the crashes….

HTH

DavidRindner
Where is the HDR image is added?

Add a light, set it to be an Area light. And plop in your HDR map in the Area Light tab.

Following directions from Help on VEX Global Illumination does not seem to work

I have one box without a top. With shere inside of it.

I added Light Template. Created VEX Global Illumination light SHOP. Converted six pack HDR to RAT . Added that RAT to the above light SHOP. In VEX GI SHOP set its Irradiance to Amb OC.
Assigned the SHOP to Light Template object. My Mantra ROP is set to Physically Based.

The scene renders black. I can see objects in alpha but no illumination in RGB. No illumination of the scene.

DR

DavidRindner
Following directions from Help on VEX Global Illumination does not seem to work
I have one box without a top. With shere inside of it.
I added Light Template. Created VEX Global Illumination light SHOP. Converted six pack HDR to RAT . Added that RAT to the above light SHOP. In VEX GI SHOP set its Irradiance to Amb OC.
Assigned the SHOP to Light Template object. My Mantra ROP is set to Physically Based.
The scene renders black. I can see objects in alpha but no illumination in RGB. No illumination of the scene.
DR

VEX GI Light Shader is not PBR compatible. It's designed for Micropoly engine. Env Light proposed by WolfWood is a good PBR companion.


hth,
skk.

Maybe I should just stick to Maya when it comes to rendering. Mantra is too frustrating.

Don't want to be rude, but the level of frustration in almost each of your ~350 posts indicates that this might be a reasonable option for you. At least I would consider this on your place.

Houdini shading and lighting is just very hard to understand. Material creation is exceedingly difficult, in comparison to MayaMentalRay materials.
In prebulit materials there is a Subout tile. Where Surface, displacement, and other shaders are included. However , when I try to build a similar shader in VEX, there is no Subout tile. How is it created? It is not a subnetwork.

This EnvLight , what is that refering to. THere is no EnvLight in SHOP Mantra LIghts. Likewise there is no EnvLight in OBJ Lights. There is a option under area light, but the results of putting HDR RAT env map into the field are terrible.

When Mantra is in PhotoMap mode, what is suppoused to act as a photon emitter? Light, object.

How is IBL done in Mantra. I am looking for similar method as Maya Mental Ray with FG.

DR

However , when I try to build a similar shader in VEX, there is no Subout tile. How is it created? It is not a subnetwork.

Hi David. Create a Material node and jump inside. From there Tab > Mantra Surface > VEX VOP Surface SHOP (or whatever else you wanna plug into the suboutput such as displacement shader).

The Environment Light is right there on the shelf, or in a bit more roundabout way: Tab > Light > set it to Area Light > set Area Shape to Environment. You're using PBR it sounds like, so just put the HDR rat into the Area Map field. You don't need to mess with Area Samples, that has no effect in PBR. If you have a mantra ROP set to be photonmap generator, you can use the HDR map alone to cast photons, no other lights needed.

In prebulit materials there is a Subout tile. Where Surface, displacement, and other shaders are included. However , when I try to build a similar shader in VEX, there is no Subout tile. How is it created? It is not a subnetwork.

That's because a shader types / properties etc are not materials ! In a shop tab > manager > material ! Materials are the containers for you surface shaders , properties & more.

This EnvLight , what is that refering to. THere is no EnvLight in SHOP Mantra LIghts. Likewise there is no EnvLight in OBJ Lights. There is a option under area light, but the results of putting HDR RAT env map into the field are terrible.

The environment light is a Light , not a shop of any type .look at the top lighting tab in the UI.

The results I am getting are inconsistent with Docs or assistance I am getting. So my frustration comes from lack of millage I am getting.
I have a simple scene with few thousand polys, one Area Env light with RAT HDR texture.
My rendering is over one hour per frame, and memory usage is above 4gb with PBR, but not that much better with micropoly rendering. I think thats pretty much absurd, regardless of what package.
Simple things like making materials don't work. I've been making materials in Maya and in MAX before for years. I cannot make a simple VEX Blinn material that works. The VEX Surface SHOP is simple. It has a Lighting Model, set to Blinn. It has one texture tile referencing a 16 bit TIFF. UV tile with S and T connected to Texture tile. That material renders black. As soon as texture tile was added, it stopped being shaded.
It can't be so complicated.

Can you post a scene? We routinely render thousands of polys and huge volumes in a production environment (with micropoly) and seldom crack 3gb. PBR, sure - thats another story - but micropoly should provide fast results.


What are you rendering? Any chance of an image? We'd love to help you debug your problem!

Jason.

PS. What version/platform are you running?

Here is the file.

This is the lighting and shader dev file for my RealFlow/Houdini flash flood that I posted some time back.

I think I remember the flash flood clips, twas very cool.

Your scene has a few setup issues. When you put the Environment Light into the scene, you don't need to move it or scale it.
Shader: your bump Texture node is going directly into the Normals of your Lighting Model VOP. That won't work. It needs to go from the texture, to a Displace Along Normal, and then into the Lighting model. I don't have access to your textures so I can't see how it's supposed to look, or wether there were other problems.

Edited the file a bit. This is a PBR setup, I'm a little rusty with the traditional GI method, I might give it a go though. Below render was 11min on a 1.6ghz core2duo lappy (memoray usage ~330MB). Not blazing fast but maybe workable…

THX

OK, but material still renders as a black hole. No shading, no illumination.

In VEX, inserted Displace Along Normal between Lighting Model and bump texture tile. Piped Displace Along into nN of Lighting Model. The geometry with this shader still renders black. It renders fine when textures are diconnected. The texture maps are 16 bit TIFFs w/o LZW. Is it a requirement to convert them to RATs?

Should color and spec. texture tiles be piped through another tile?

Another issue is various texture channels. What gets me is that I am looking at Lighting Model tile as Maya material. In Maya mats there are channel for color, diffusion, spec, etc.. Same in MAX

In Lighting Model there is diff(for color), spec. So what channell controls the diffuse value, sence diff is color? Its like there are not enough channells.

My next big stumbling block is how Particles are associated with DOPs. The two are separate, and I do not understand the proccess of getting them to share data. In POP network there is so little under Forces menu. All the dynamic fields are in DOPs. Is DOP brought into POP so particles can be affected by fields, and solvers? Or vice versa?

Just to be sure we're on the same page, it should look something like this…



But it's possible that Houdini is not getting along with those TIFFs. Go ahead and convert them, can't hurt to try. As for your shader, there is nothing wrong with where you've got your textures plugged. BUT… that Lighting Model VOP is *not* your shader, don't think of it like that. It's just a small building block. If you go inside the vopnet of something like Basic Surface (in the material pallette), you can see there is a lot of stuff going on to provide the functionality in the shader.

Thank you

What is that scale node. Becouse the scale node that I am getting in VEX is different with different variables. Which tile did you put down, and what is its pourpouse? What is being scaled?

I looked at the construction of Basic Surface. Ummm. Its ununderstandable. At least by me. I don't get how this materials are put together.

Then there are suboutput nodes in SHOP. In Help the instructions are as follows
Creating your own material and adding it to the gallery file

1.

In the SHOP network, create a Material node.
2.

Create one or more SHOPs inside it, and connect it to the suboutput node.

If you create more than one SHOPS, select them both, click and select Collapse to merge the SHOPs into a new material.


There is no Collapse option when RMB on multiple selected SHOPS . So where is this Collapse, and how is SUBOUT created.
To make matters worse HELP on SUBOUT is unavailable. With following message.

Not Found

The resource could not be found.
WSGI Server

OK took care of Collapse. Still don't see which node you used for scale.

DavidRindner
OK took care of Collapse. Still don't see which node you used for scale.

It's a Paramter VOP, of proper type, and named as “scale”, If you RMB on a node, there is a “Create Inputs Paramters” which creates all of them for a particular VOP. MMB on any input to create a single one properly typed and named.

DavidRindner
I looked at the construction of Basic Surface. Ummm. Its ununderstandable. At least by me. I don't get how this materials are put together.

This sounds a little bit strange considering that you said you are experienced in shading. There's really nothing there very different from what one might see in XSI's RenderTree or in Slim or in HyperShade.
You should take your time to read the docs, your problems arise from lack of basic understanding of stuff which is either documented in the help or on this forum or on odforce.
You can also try this for a fast introduction to Mantra:
http://www.digitaltutors.com/store/product.php?productid=3557 [digitaltutors.com]

Dragos

DavidRindner
I looked at the construction of Basic Surface. Ummm. Its ununderstandable. At least by me. I don't get how this materials are put together.

It can be tough to figure out what's going on in a vopnet at a glance. Even shaders that I made myself, I often find myself scratching my head when I revisit them. “What was I trying to do here…?” Really helps to label nodes descriptively and organize the vopnet with network boxes…

Not sure about the collapse thing, maybe it used to be in the menu and got taken out. You can just hit shift-c and it will collapse your selected SHOPs into a Material, suboutput and all. And SYmek already explained about the Parameter node. :]