Hi,

I Just started playing around with image based lighting in Mantra – everything works nice so far but when I try to replace the environment light with a template light (with a vex GL light shader applied) the render remains black when rendering in PBR mode. Well it works with Raytracing , and also If I apply a environment box to the scene – but is there any other way to set up image based lighting in Mantra (PBR) with the vex Gl shader but without using a environment box ? Or does the PBR engine really needs something in the scene to work with, since it is physically based?

Your scene file is built using Houdini 10 methods. Were you following a tutorial or lesson?

First of all, you can't use the Light Template technique using the Vex GI Light SHOP shader with PBR. It doesn't work as you found out.

Houdini11 changed the way you set up image based lighting. It is very easy now. You no longer need to resort to the Light Template to get performance when using Mantra in Micropolygon or Raytrace mode and it works with all three Mantra render engines with similar results.

You use an Environment Light.

Upon further inspection of your file, you are using an old Houdini10 Mantra Output ROP driver as well.

Please replace that with a new Mantra ROP and set up the PBR settings to match the old one then discard the old one.

Hi Jeff,
Thanks for your fast response on my question. I watched Peter Quint's tutorials about Global Illumination on Vimeo, which led me to this setup. I already red a bit about the new lighting features in Houdini 11 but unfortunately my current Hardware doesn’t work well with H11. So I’m still using Houdini 10.0.595 – guess it’s high time for an upgrade. I’m actually pretty new to Houdini and 3d animation in general (well, I worked a bit with Blender in the past) but I’m often stuck in situations where I’m not really sure if I’m doing things the right way or think there has to be a better/other way to do this or that…. So are there also some tutorials out there which cover some general workflows how to set up and manage things in 3d? Houdini offers many different ways to archive different results – it’s just sometimes a bit difficult as beginner to understand why things are done the way they are.

As for Houdini11, you may want to turn off High Quality shading as that seems to offer some issues with graphics in the viewport. Make sure to use a recent build of Houdini. The latest production build is good as well as recent daily builds.

If you are stuck with Houdini10, your set up works well with Micropolygon and Raytrace render engines.

For PBR, you need to use the Environment Light to reference the HDR image as an enviornment map and disable your Light Template object for PBR passes.

I just tried out the newest release of Houdini 11 and was really surprised seeing it work. The last time I tried H11 I had major issues with the viewport performance and thought my video card finally ran out of capacity
(old fx1400go ). As you said, it’s really easy now to set up image based lighting and rendering seems to be a bit faster as well. thanks for your tips