ygalula Posted February 7, 2009 Share Posted February 7, 2009 Hello, I"m trying to understand how Mantra renders volumetrics by diving into the Heavy Smoke tool from the FX tools shelf. Prior to Houdini 9.5, you needed to write a fog VEX shader in order to calculate the integration through the volume, but is seems that in 9.5 (at least in the Smoke example shader) the shader is a 'regular' surface shader (and Mantra somehow slices up the volume for you). What I'm asking is how Mantra knows it's rendering a volume and needs to start slicing it? If you'll look at the surface shader you might think that functions like "metaimport" are called once per pixel (which is obviously not true)... Thanks Quote Link to comment Share on other sites More sharing options...
johner Posted February 7, 2009 Share Posted February 7, 2009 Hello,I"m trying to understand how Mantra renders volumetrics by diving into the Heavy Smoke tool from the FX tools shelf. Prior to Houdini 9.5, you needed to write a fog VEX shader in order to calculate the integration through the volume, but is seems that in 9.5 (at least in the Smoke example shader) the shader is a 'regular' surface shader (and Mantra somehow slices up the volume for you). What I'm asking is how Mantra knows it's rendering a volume and needs to start slicing it? If you'll look at the surface shader you might think that functions like "metaimport" are called once per pixel (which is obviously not true)... Thanks Right, Mantra has true volumetric rendering now. Mark Elendt (one of Mantra's main developers) goes into some great detail about how volume rendering works in this Mantra Masterclass. There's some great stuff about Physically-Based Rendering in there as well. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.