See the light before rendering

odastein

I don't know how to see what is the light is like before rendering. I understand that there's a "spot render" that allows to do that, but the only thing I found there was the instant "Basic open GL" render, and it doesn't show at all the light level in Iray (For instance in basic GL, the scene seems brightly illuminated, but when I try to render it in Iray, I can barely see anything). If I start a regular render, it takes 15-20 minutes before I have a first view of the scene, and can notice that I need more/less/different light, adjust, launch a new render, etc...

So, I can I see what the lights will look like before rendering?

 

LosingSignal

odastein said:

I don't know how to see what is the light is like before rendering. I understand that there's a "spot render" that allows to do that, but the only thing I found there was the instant "Basic open GL" render, and it doesn't show at all the light level in Iray (For instance in basic GL, the scene seems brightly illuminated, but when I try to render it in Iray, I can barely see anything). If I start a regular render, it takes 15-20 minutes before I have a first view of the scene, and can notice that I need more/less/different light, adjust, launch a new render, etc...

So, I can I see what the lights will look like before rendering?

 

Two ways.  One is that the Spot Render tool is under the Tools menu.  There's also an icon for it (probably) somewhere near the icons for the other tools, and it looks like a little camera with a mouse pointer over the top right hand side.  Either way, you pick the point you want to render in the viewport, hold the left mouse button, and drag a square over the area.

The other way is to set your viewport to NVIDIA Iray.  Click the ball on the left of the camera selection in the viewport, and NVIDIA Iray should be the last item on the menu.  It takes a bit, but that will show what the entire camera area looks like in Iray.

odastein

Thanks. In fact, I knew where "spot render" was, but I hadn't realized that you could select part of the viewport for rendering. I thought that a "spot render" was some sort of very quick minimal render of the whole image, like basic GL, not a complete render of part of the image. So, it's not surprising that I couldn't make it work.

odastein

In fact, it turned out to not being very useful in this case. The "spot render" takes way less time to complete than a complete render, but about as much time to start producing an image (15 minutes or so), and since as soon as I see the the "first draw" of the image, I can tell that there's not enough light, it doesn't really make a difference.

And my laptop doesn't like much setting the viewport to Iray when there are too much stuff to render, apparently.

Paintbox

If your scene takes up a lot of memory it will take some time before it starts rendering. Something like scene optimizer can help with that by removing or shrinking maps. Do you render GPU or CPU?

odastein

Paintbox said:

If your scene takes up a lot of memory it will take some time before it starts rendering. Something like scene optimizer can help with that by removing or shrinking maps. Do you render GPU or CPU?

I put "scene optimizer" onmy wishlist for future reference. At the moment, I think I've enough troubles with understanding the basic functions of Daz 3d without trying to understand how such a tool could be used.

As for your question : both GPU and CPU, I guess, since both boxes are checked.

Tobor

For faster render startup begin a regular render to a new window. After you see the first vestiages of an image cancel the render, but not close the window. This keeps the scene database in memory so that it doesn't have to reload each time you do a render. (It will only reload if you add or remove geometry or textures, but not lights, cameras, or procedural shaders).

Since you are main interested in the lighting you can tey hiding (click the eye icon) of scene elements that aren't involved in the test. Things like hair, especially micro fiber, or other complex gemoetry and transparencies can add considerable time to building the scene database. I was working on a scene tonight with very complex hair and when it was shown the scene database was built in about two minutes; just hiding the hair produced a first iteration in under 20 seconds.

These shortcuts work whether you're doing a spot render or you use the nVidia Iray render option in the view window. Unlike the scene optimizer methods they don't affect the quality of the render by reducing the size of textures. Sometimes you really do need a 4K (or even 8K) texture.

CGHipster

A simplified way is to use the aux viewport in iray rendered mode, not only will you get a preview of the scene in iray but because your scene is already loaded in the iray db your final render will begin faster having not had to load the scene into the db for iray to process.

odastein

Tobor said:

For faster render startup begin a regular render to a new window. After you see the first vestiages of an image cancel the render, but not close the window. This keeps the scene database in memory so that it doesn't have to reload each time you do a render. (It will only reload if you add or remove geometry or textures, but not lights, cameras, or procedural shaders).

This is a nicez trick. I'm going to use it.

odastein

CGHipster said:

A simplified way is to use the aux viewport in iray rendered mode, not only will you get a preview of the scene in iray but because your scene is already loaded in the iray db your final render will begin faster having not had to load the scene into the db for iray to process.

 

I wasn't doing that because it would more or less freeze my computer. For some reason, it doesn't anymore, so that's what I do now.