Hello everyone,

I've come across a problem I've never encountered before. Unfortunately, all the forum posts I could find here and on odforce didn't fix this issue.

For some reason my volumes look and shade completely different in the Render View Pane compared to the actual render.


I am using the micropolygonal render engine for both. The preview render is off, so I'm not comparing raytracing to micropoly.

It seems like it interprets the lights differently. In my actual scene the render time in the render view is around 6 minutes and everything looks as it should, but when rendering to disk or MPlay the render time decreases and I get a horrible result.
I've tried to change the Gamma Settings but I never got the same result. I used a new mantra rop, same problem. Then, I wondered if my file was corrupted and imported my sim into a new scene. The same bad result.

Next I created a simple volume from Tommy and the same problem occurs.

I've attached the simple file and a screenshots that show my problem. You can also see the differences in render speed (although I used 1/3 resolution for the screenshots)

Does this happen to anybody else? Or does somebody know how to fix this?

A few minutes later and I actually found the root of the problem. The lights are all set to Depth Map and not ray traced shadows.
When using ray traced shadows this difference doesn't happen.

Which makes me wonder if this is a bug and mantra messes something up with the shadow maps generation for the final render.

Maybe somebody could test and see if this only happens on my machine.

IPR is always using raytracing and raytrace shadows. To preview micropoly you'd have to render to MPlay.
There is a render property parameter, that you can add to your mantra to disable the forced raytraced shadows though:
vm_iprraytraceshadows -> “Always Use Raytraced Shadows in Preview Mode”

Thank you for your answer.
I was under the impression that when you disable the preview button, mantra would use the same settings as if you would render to mplay.
Especially because it does generate shadow maps before starting to render which seems unnecessary if it doesn't use them.

But I still feel like I need to change something, since the handbook advises you to use shadow maps instead of raytraced shadows and I can't seem to get them to work properly.

No_ha
But I still feel like I need to change something, since the handbook advises you to use shadow maps instead of raytraced shadows and I can't seem to get them to work properly.

No one uses shadow maps anymore.

No_ha
But I still feel like I need to change something, since the handbook advises you to use shadow maps instead of raytraced shadows and I can't seem to get them to work properly.

they are generated within your spotlight cone angle and I think within near/far region, so if you are using any other type of light make sure that the spotlight cone angle still covers your volume

that being said, I haven't used them for ages either

Thank you all very much.
It eases my mind, that you don't use shadow maps anymore, because I had already given up and am using raytraced shadows now.
I probably read too much outdated material.