volume shading

[ela1995]

I tried to create a muzzle flash base on this vimeo. In Houdini, I converted the polygon to volume, but I don't know how to apply material to it since the effect is not create by Pyro DOP Network. I tried either pyro post porcess and flame material, both didn't work. How should I apply the material properly?

 

shading volum.hipnc

[wakimsan]

Hi Doanh, 

I haven't really looked through the tutorial, but I can tell you're having some issues with your fields. At the moment you only have a vdb converted into a volume called "flame".
The pyroshader you applied to this volume tries to read the fields; "heat" for intensity and "temperature" at the "fire temperature field" tab. That's usually the default setting because a pyro sim will usually produce those fields for you automatically. 

You probably only want the intensity to be controlled by your flame field. If you type in "flame" in each of these fields(intensity & temperature) in the shader, you should get some visible muzzle flash in your render. 

cheers
 

[ela1995]

9 hours ago, wakimsan said:

Hi Doanh, 

I haven't really looked through the tutorial, but I can tell you're having some issues with your fields. At the moment you only have a vdb converted into a volume called "flame".
The pyroshader you applied to this volume tries to read the fields; "heat" for intensity and "temperature" at the "fire temperature field" tab. That's usually the default setting because a pyro sim will usually produce those fields for you automatically. 

You probably only want the intensity to be controlled by your flame field. If you type in "flame" in each of these fields(intensity & temperature) in the shader, you should get some visible muzzle flash in your render. 

cheers
 

Thanks, your method works. Is it possible to do it the 'Pyro Post-Process' SOP? I wire the 'PPP' SOP after convertVDB, it just simply disappear.

[wakimsan]

15 hours ago, ela1995 said:

Thanks, your method works. Is it possible to do it the 'Pyro Post-Process' SOP? I wire the 'PPP' SOP after convertVDB, it just simply disappear.

The pyro post process node applies its own material to the object at SOP level. If you look at the primitive attribute "shop_materialpath" you can see which material overrides the one you applied at OBJ level. It's actually a material within a matnet in this node. If you uncheck "assign render material", the node will not apply a material.

However, if you want the post process node to work properly with a similar shader setup - you can go to the "Bindings" tab of the post process node. And, just like we did with the shader, type in "flame" in the temperature field.
Make sure "Assign Render Material" is checked ON. This method will allow the post process node to apply the intended material and allows you to control the (shader)attributes in sop context.

cheers