Ive asked this on odforce expecting an answer almost immediately but no one has answered (maybe the more experienced users missed it).

But my question is after all the years i have been tinkering with Houdini one thing i still do not understand properly is displacements. The setup, the workflow.

I understand the way to connect it with materials and applying them to objects. I have no problem understanding to get it work. I just cant get it to work properly.

I dont understand when you render an object with displacement, how do you create more polys at render time? (surely there must be a better way other than using a subdivde sop (with the render flag on) .)

Thanks guys, i really have looked around and opened alot of files and still dont get it. (even in some files, they dont use a subdivide sop yet its very smooth.)


-andrew

hey

at object level, on your Geometry go to the Render tab, go to the Geometry tab under that, there you will find a “Polygons as Subdivision” toggle that on and your on your way

hope that helps

jason

If you want more detail in render time using displacement, try to raise up the shading quality from the render tab in a geo node, this dice the primitive into micropolygons to properly displace the source geometry.

as alejandro says: displacement (or its quality) has nothing to do with a number of polygons. The size and amount of micropolygons count.

So, the main topic here is dicing. Mantra9 has a wonderful control over dicing process. Check out anything that is related to it, like this Help page:
http://www.sidefx.com/docs/houdini9.5/rendering/dicing [sidefx.com]

Of course some of rendering properties also count:
http://www.sidefx.com/docs/houdini9.5/props/mantra9_1 [sidefx.com]

There was a great thread that covered this over on Odforce. I know several people uploaded files showing several effects using displacement.



Rob

Since i asked this question, i have gone through most of the issues that concern my setup.

For those visiting this thread in the future. Here are a few tips i have came across including this thread.

No need to up the shading quality at first. Keep it at 1 for test (super fast), should the displacement not capture all the detail you want/know is there you will need to raise this feature (this is the main feature that will increase render time). Search for thread about this feature should you want to know more.

Use the simple displace shader with the setting at grey = No displacement. No need for the VEX SHOP that was written for 8.1 and beyond.

If you get slightly weird results you may need to raise your displacement bounds.

Polygons as Subdivision is the way to go, but make sure you accommodate for this if you are using Zbrush with the SubDiv feature on level 1 (it should inflate you model slightly, exaggerating the points), then generate the displacement.

If you can, save your high res texture as a RAT as this will cost a little at render time.

With all these in mind, here is a quick test with my default bolthead guy (i use him for everything ). Im not entirely happy with the result but i know that because the displacement was generated without the use of the subDiv feture in Zbrush.

I didnt note the exact time but it was under 30 seconds. Shading quality 3.