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Showing results for tags 'prman'.
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shop_displacepath on per primitive base?
eldericmk posted a topic in Lighting & Rendering + Solaris!
Hi there, I'm trying to wrap my head around renderman 20 in houdini 15.5. Now there's a tricky thing with displacements going on. When building stuff, I usually group the entire object in a single geometry node via subnet and combines, applying materials via the material SOP and specific groupings of the underlying geometry. this in turn creates a string attribute on the selected primitives with name “shop_materialpath” and the given path to the pxrWhatever shader. stuff shows up in RIS renders, everything behaves as expected. fine. this would behave equally, if I just added the “shop_materialpath” via AttributeCreate and the proper path to the shader by hand on a primitive. however, now I want to displace something. the only working way in renderman 20 seems to be to create a pxrDisplacement with some input (f.e. pxrWorley) and add the rendering parameters “Displacement Shader” (shop_displacepath) and “Displacement Bound” (ri_dbound) to the geometry node in /obj. Apply the shader, set bound > 0, displacement shows up in renders. fine. BUT: Now I thought: “Hah. Just transfer these parameters on a primitive base via AttributeCreate as well, done.”. However this doesn't seem to work. Instead I have to extract the geo into a second geometry node in /obj via ObjectMerge and again apply the said parameters on the top-level geometry node itself. Are “shop_displacepath” and “ri_dbound” not assignable to primitives by hand? Or am I missing a crucial step? Perhaps something else has to be applied as well? Any Ideas? -Marcus -
Hi, i love the shading/material and lighting/rendering part of the pipeline,in a word,the realism part of CG, yesterday i bought the book "The RenderMan Shading Language Guide", i heard this renderer is the industry standard(is it?) so for now i want to focus on and start learning how to write shaders with it : 1 - how do you evaluate the book? 2 - i'm starting from scratch but i know the C language a little,should i know C before RenderMan? 3 - i heard RenderMan is similar to VEX,is it really? 4 - how do you compare RRMan with Mantra?(they say PRman is THE software itself) 5 - is this book a good starting point for using PRman IN HOUDINI?i mean is the code constant no matter where and in which software it's used? 6 - and finally, if the book is not good then what sources do you suggest to master the renderman shading language?something like fxphd course on renderman?
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Hi, recently, I'm using Houdini to make clouds. I use the Houdini self tool "Pyro FX->Volcano" to emit smoke from a lot of spheres, and then I can make the clouds I like. Please see the attachment picture 1, which is rendered by Mantra. Because I feel it quite slow when using Mantra, and I have Pixar's RenderMan in hand, so I try to render my clouds using PRMan to speed up rendering. But, I can't get what I want, please see attachment picture 2. I know I need to using Light Template when using PRMan, does I miss anything else for successfully rendering Pyro in PRMan? Thanks a lot.
