I am rendering some simple test scenes with Mantra. I am using the apprentice version of houdini (version 12, on windows). It seems I am doing something wrong - not sure what.

1) I set up my scene, and go to the mantra node in \out. I change a few settings and click the “Render” button at the top of the “Render View”, and I see it rendering an image. This image looks fine, and I can save it by right clicking.

2) However, now I want to render an animation. So I set up the “Output” parameters on the mantra node, and click the “Render” button at the parameters window for the mantra node. Each frame now takes _much_ longer to render, and the quality seems to be about the same.

What is the difference between these two Render buttons?

Otherwise they are the same, except if the Render View pane is in “preview”-mode, then it always uses the raytrace render engine, even if the ROP is set to use a micropoly engine.

(The progressive refinement needs to be done in raytrace mode)

The actual engine being used is shown overlaid in parentheses on the left upper corner of the Render View pane, e.g. /out/mantra_ipr(raytrace)

Thanks for the quick reply. That helps to explain a few things.

I am also finding that there is erratic behavior with mantra getting a license. When I start a new file and try to render something, the mantra nodes is often red - with a message saying that it can not get a valid license. Then all of a sudden it starts working.

Can I just confirm that with an apprentice version of houdini, we should still be able to render using any of the rendering methods in mantra - micropolygon, ray trace, etc. The only limitation is the size and the houdini logo. Is that correct?

Also, what about wren?

phtj
Can I just confirm that with an apprentice version of houdini, we should still be able to render using any of the rendering methods in mantra - micropolygon, ray trace, etc. The only limitation is the size and the houdini logo. Is that correct?

Heck yes!
go crazy.

When I try yo use Wren I get:

No licenses could be found to run this application.
Please check for a valid license server host

The license manger shows two licenses:
- Houdini Master NonCommercial
- Render NonCommercial

I find that the Render View usually keeps a copy of Mantra running that's holding onto a license, so when I try to render separately, it'll fail to get a license. If I hit the red stop button in the Render View, it kills the Mantra process, (if it doesn't, you can kill it yourself in the Task Manager in the Processes tab), freeing up the license. Then the render node seems to work.

Hopefully that helps!