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Author Topic: brief instructions that controlling the clump size and density of distribution b  (Read 941 times)

cc8boy

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Hello eveyone,
I'm going to make a very very huge aera of grass in my project.
To save system memory I have an idea :
1. To use very small clumps of grass sample for the grass that close to the camera. The small clumps would be very dense.
2. To use medium clumps of grass sample for the grass that middle distance to the camera. The medium clumps should be medium dense.
3. To use very large clumps of grass sample for the grass far from the camera. These very large clumps should be less dense.

I've read this tutorial . http://www.itoosoft.com/tutorials/tutorial_lod.php?back=level%3DIntermediate%26page%3D1%26search%3Ddetail%26tag%3Dfp
But this LOD tutorial is just about one single tree not about clumps of objects.

Can you give me some brief instructions that controlling the clump size and density of distribution at the same time by distance of cameras ?

We are working hard in virtual effects in 3DSMAX. Welcome to our website in China.

Paul Roberts

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Hi,

Please see the attached file for a possible solution. It uses ForestLOD to change patch sizes and Distance Density Falloff to reduce the density based on camera distance. A few notes:

- You can use Forest LOD to pick patches instead of single trees. The procedure is the same as shown in the tutorial
- For both LOD and Distance Falloff I've activated Use Environment Range. This means that both these controls are linked to the camera's Environment Range > Near/Far settings.
- In this example I've switched LODs at 33% intervals.
- To match this, step the Density Falloff curve as shown in the image below.



I hope that helps, please let me know if you have any further questions.

Many Thanks,

Paul
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Michal Karmazín

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Hi,

Another possible approach would be to set Distribution Map - Density values accordingly to the smallest clump size and enable the Collisions feature to reduce bigger ones (as most probably those will have nearly circular shapes, it'll do the job nicely). In my sample scene Collisions - Radius values around 50% seems to be working fine. Attaching screenshots.

Hope you'll find it useful.

Best regards,

Paul Roberts

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↑↑↑↑↑↑↑↑↑↑

Michal's approach is much easier :)
Paul Roberts
iToo Software

cc8boy

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Thanks for your replies. I'll try both in my terrains. It's very usefull in creating large aera of grass.

Best wishes.
We are working hard in virtual effects in 3DSMAX. Welcome to our website in China.

Rokas

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could we have Michals scene?
Rokas
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Michal Karmazín

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Hi,

Sure, please find attached sample scene showing this possible set-up. Let me mention, that's not recommendable to use such work-around having items with big size differences (density will vary a lot) or on large areas (overall the Collisions feature might cause a significant performance hit on large distributions) as the very low efficiency of this method (all items need to be generated and later a huge amount of those might be discarded and that'll take time & system resources) might be problematic on such scenes. It's meant as an "quick & easy" alternative, that in some situations might be handy.

Best regards,